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+'\"
+'\" Smithsonian Astrophysical Observatory, Cambridge, MA, USA
+'\" This code has been modified under the terms listed below and is made
+'\" available under the same terms.
+'\"
+'\" Copyright 1991-1998 by Bell Labs Innovations for Lucent Technologies.
+'\"
+'\" Permission to use, copy, modify, and distribute this software and its
+'\" documentation for any purpose and without fee is hereby granted, provided
+'\" that the above copyright notice appear in all copies and that both that the
+'\" copyright notice and warranty disclaimer appear in supporting documentation,
+'\" and that the names of Lucent Technologies any of their entities not be used
+'\" in advertising or publicity pertaining to distribution of the software
+'\" without specific, written prior permission.
+'\"
+'\" Lucent Technologies disclaims all warranties with regard to this software,
+'\" including all implied warranties of merchantability and fitness. In no event
+'\" shall Lucent Technologies be liable for any special, indirect or
+'\" consequential damages or any damages whatsoever resulting from loss of use,
+'\" data or profits, whether in an action of contract, negligence or other
+'\" tortuous action, arising out of or in connection with the use or performance
+'\" of this software.
+'\"
+'\" Graph widget created by Sani Nassif and George Howlett.
+'\"
+.TH graph n BLT_VERSION BLT "BLT Built-In Commands"
+.BS
+'\" Note: do not modify the .SH NAME line immediately below!
+.SH NAME
+graph \- 2D graph for plotting X\-Y coordinate data.
+.SH SYNOPSIS
+\fBgraph\fI \fIpathName \fR?\fIoption value\fR?...
+.BE
+.SH DESCRIPTION
+The \fBgraph\fR command creates a graph for plotting
+two-dimensional data (X\-Y coordinates). It has many configurable
+components: coordinate axes, elements, legend, grid lines, cross
+hairs, etc. They allow you to customize the look and feel of the
+graph.
+.SH INTRODUCTION
+The \fBgraph\fR command creates a new window for plotting
+two-dimensional data (X\-Y coordinates). Data points are plotted in a
+rectangular area displayed in the center of the new window. This is the
+\fIplotting area\fR. The coordinate axes are drawn in the
+margins around the plotting area. By default, the legend is displayed
+in the right margin. The title is displayed in top margin.
+.PP
+The \fBgraph\fR widget is composed of several components: coordinate
+axes, data elements, legend, grid, cross hairs, pens, postscript, and
+annotation markers.
+.TP 1i
+\f(CWaxis\fR
+The graph has four standard axes (\f(CWx\fR, \f(CWx2\fR,
+\f(CWy\fR, and \f(CWy2\fR), but you can create and display any number
+of axes. Axes control what region of data is
+displayed and how the data is scaled. Each axis consists of the axis
+line, title, major and minor ticks, and tick labels. Tick labels
+display the value at each major tick.
+.TP 1i
+\f(CWcrosshairs\fR
+Cross hairs are used to position the mouse pointer relative to the X
+and Y coordinate axes. Two perpendicular lines, intersecting at the
+current location of the mouse, extend across the plotting area to the
+coordinate axes.
+.TP 1i
+\f(CWelement\fR
+An element represents a set of data points. Elements can be plotted
+with a symbol at each data point and lines connecting the points.
+The appearance of the element, such as its symbol, line width, and
+color is configurable.
+.TP 1i
+\f(CWgrid\fR
+Extends the major and minor ticks of the X\-axis and/or Y\-axis across the
+plotting area.
+.TP 1i
+\f(CWlegend\fR
+The legend displays the name and symbol of each data element.
+The legend can be drawn in any margin or in the plotting area.
+.TP 1i
+\f(CWmarker\fR
+Markers are used annotate or highlight areas of the graph. For
+example, you could use a polygon marker to fill an area under a
+curve, or a text marker to label a particular data point. Markers
+come in various forms: text strings, bitmaps, connected line
+segments, images, polygons, or embedded widgets.
+.TP 1i
+\f(CWpen\fR
+Pens define attributes (both symbol and line style) for elements.
+Data elements use pens to specify how they should be drawn. A data
+element may use many pens at once. Here, the particular pen
+used for a data point is determined from each element's weight
+vector (see the element's \fB\-weight\fR and \fB\-style\fR options).
+.TP 1i
+\f(CWpostscript\fR
+The widget can generate encapsulated PostScript output. This component
+has several options to configure how the PostScript is generated.
+.SH SYNTAX
+.DS
+\fBgraph \fIpathName \fR?\fIoption value\fR?...
+.DE
+The \fBgraph\fR command creates a new window \fIpathName\fR and makes
+it into a \fBgraph\fR widget. At the time this command is invoked, there
+must not exist a window named \fIpathName\fR, but \fIpathName\fR's
+parent must exist. Additional options may be specified on the
+command line or in the option database to configure aspects of the
+graph such as its colors and font. See the \fBconfigure\fR operation
+below for the exact details about what \fIoption\fR and \fIvalue\fR
+pairs are valid.
+.PP
+If successful, \fBgraph\fR returns the path name of the widget. It
+also creates a new Tcl command by the same name. You can use this
+command to invoke various operations that query or modify the graph.
+The general form is:
+.DS
+\fIpathName \fIoperation\fR \fR?\fIarg\fR?...
+.DE
+Both \fIoperation\fR and its arguments determine the exact behavior of
+the command. The operations available for the graph are described in
+the
+.SB "GRAPH OPERATIONS"
+section.
+.PP
+The command can also be used to access components of the graph.
+.DS
+\fIpathName component operation\fR ?\fIarg\fR?...
+.DE
+The operation, now located after the name of the component, is the
+function to be performed on that component. Each component has its own
+set of operations that manipulate that component. They will be
+described below in their own sections.
+.SH EXAMPLE
+The \fBgraph\fR command creates a new graph.
+.CS
+# Create a new graph. Plotting area is black.
+graph .g \-plotbackground black
+.CE
+A new Tcl command \f(CW.g\fR is also created. This command can be used
+to query and modify the graph. For example, to change the title of
+the graph to "My Plot", you use the new command and the graph's
+\fBconfigure\fR operation.
+.CS
+# Change the title.
+\&.g configure \-title "My Plot"
+.CE
+A graph has several components. To access a particular component you
+use the component's name. For example, to add data elements, you use
+the new command and the \fBelement\fR component.
+.CS
+# Create a new element named "line1"
+\&.g element create line1 \\
+ \-xdata { 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 } \\
+ \-ydata { 26.18 50.46 72.85 93.31 111.86 128.47 143.14
+ 155.85 166.60 175.38 }
+.CE
+The element's X-Y coordinates are specified using lists of
+numbers. Alternately, BLT vectors could be used to hold the X\-Y
+coordinates.
+.CS
+# Create two vectors and add them to the graph.
+vector xVec yVec
+xVec set { 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 }
+yVec set { 26.18 50.46 72.85 93.31 111.86 128.47 143.14 155.85
+ 166.60 175.38 }
+\&.g element create line1 \-xdata xVec \-ydata yVec
+.CE
+The advantage of using vectors is that when you modify one, the graph
+is automatically redrawn to reflect the new values.
+.CS
+# Change the y coordinate of the first point.
+set yVector(0) 25.18
+.CE
+An element named \f(CWe1\fR is now created in \f(CW.b\fR. It
+is automatically added to the display list of elements. You can
+use this list to control in what order elements are displayed.
+To query or reset the element display list, you use the element's
+\fBshow\fR operation.
+.CS
+# Get the current display list
+set elemList [.b element show]
+# Remove the first element so it won't be displayed.
+\&.b element show [lrange $elemList 0 end]
+.CE
+The element will be displayed by as many bars as there are data points
+(in this case there are ten). The bars will be drawn centered at the
+x-coordinate of the data point. All the bars will have the same
+attributes (colors, stipple, etc). The width of each bar is by
+default one unit. You can change this with using the \fB\-barwidth\fR
+option.
+.CS
+# Change the X\-Y coordinates of the first point.
+set xVec(0) 0.18
+set yVec(0) 25.18
+.CE
+An element named \f(CWline1\fR is now created in \f(CW.g\fR. By
+default, the element's label in the legend will be also \f(CWline1\fR.
+You can change the label, or specify no legend entry, again using the
+element's \fBconfigure\fR operation.
+.CS
+# Don't display "line1" in the legend.
+\&.g element configure line1 \-label ""
+.CE
+You can configure more than just the element's label. An element has
+many attributes such as symbol type and size, dashed or solid lines,
+colors, line width, etc.
+.CS
+\&.g element configure line1 \-symbol square \-color red \\
+ \-dashes { 2 4 2 } \-linewidth 2 \-pixels 2c
+.CE
+Four coordinate axes are automatically created: \f(CWx\fR, \f(CWx2\fR,
+\f(CWy\fR, and \f(CWy2\fR. And by default, elements are mapped onto the
+axes \f(CWx\fR and \f(CWy\fR. This can be changed with the \fB\-mapx\fR
+and \fB\-mapy\fR options.
+.CS
+# Map "line1" on the alternate Y\-axis "y2".
+\&.g element configure line1 \-mapy y2
+.CE
+Axes can be configured in many ways too. For example, you change the
+scale of the Y\-axis from linear to log using the \fBaxis\fR component.
+.CS
+# Y\-axis is log scale.
+\&.g axis configure y \-logscale yes
+.CE
+One important way axes are used is to zoom in on a particular data
+region. Zooming is done by simply specifying new axis limits using
+the \fB\-min\fR and \fB\-max\fR configuration options.
+.CS
+\&.g axis configure x \-min 1.0 \-max 1.5
+\&.g axis configure y \-min 12.0 \-max 55.15
+.CE
+To zoom interactively, you link the \fBaxis configure\fR operations with
+some user interaction (such as pressing the mouse button), using the
+\fBbind\fR command. To convert between screen and graph coordinates,
+use the \fBinvtransform\fR operation.
+.CS
+# Click the button to set a new minimum
+bind .g <ButtonPress-1> {
+ %W axis configure x \-min [%W axis invtransform x %x]
+ %W axis configure x \-min [%W axis invtransform x %y]
+}
+.CE
+By default, the limits of the axis are determined from data values.
+To reset back to the default limits, set the \fB\-min\fR and
+\fB\-max\fR options to the empty value.
+.CS
+# Reset the axes to autoscale again.
+\&.g axis configure x \-min {} \-max {}
+\&.g axis configure y \-min {} \-max {}
+.CE
+By default, the legend is drawn in the right margin. You can
+change this or any legend configuration options using the
+\fBlegend\fR component.
+.CS
+# Configure the legend font, color, and relief
+\&.g legend configure \-position left \-relief raised \\
+ \-font fixed \-fg blue
+.CE
+To prevent the legend from being displayed, turn on the \fB\-hide\fR
+option.
+.CS
+# Don't display the legend.
+\&.g legend configure \-hide yes\fR
+.CE
+The \fBgraph\fR widget has simple drawing procedures called markers.
+They can be used to highlight or annotate data in the graph. The types
+of markers available are bitmaps, images, polygons, lines, or windows.
+Markers can be used, for example, to mark or brush points. In this
+example, is a text marker that labels the data first point. Markers
+are created using the \fBmarker\fR component.
+.CS
+# Create a label for the first data point of "line1".
+\&.g marker create text \-name first_marker \-coords { 0.2 26.18 } \\
+ \-text "start" \-anchor se \-xoffset -10 \-yoffset -10
+.CE
+This creates a text marker named \f(CWfirst_marker\fR. It will display
+the text "start" near the coordinates of the first data point. The
+\fB\-anchor\fR, \fB\-xoffset\fR, and \fB\-yoffset\fR options are used
+to display the marker above and to the left of the data point, so that
+the data point isn't covered by the marker. By default,
+markers are drawn last, on top of data. You can change this with the
+\fB\-under\fR option.
+.CS
+# Draw the label before elements are drawn.
+\&.g marker configure first_marker \-under yes
+.CE
+You can add cross hairs or grid lines using the \fBcrosshairs\fR and
+\fBgrid\fR components.
+.CS
+# Display both cross hairs and grid lines.
+\&.g crosshairs configure \-hide no \-color red
+\&.g grid configure \-hide no \-dashes { 2 2 }
+# Set up a binding to reposition the crosshairs.
+bind .g <Motion> {
+ .g crosshairs configure -position @%x,%y
+}
+.CE
+The crosshairs are repositioned as the mouse pointer is moved
+in the graph. The pointer X-Y coordinates define the center
+of the crosshairs.
+.PP
+Finally, to get hardcopy of the graph, use the \fBpostscript\fR
+component.
+.CS
+# Print the graph into file "file.ps"
+\&.g postscript output file.ps \-maxpect yes \-decorations no
+.CE
+This generates a file \f(CWfile.ps\fR containing the encapsulated
+PostScript of the graph. The option \fB\-maxpect\fR says to scale the
+plot to the size of the page. Turning off the \fB\-decorations\fR
+option denotes that no borders or color backgrounds should be
+drawn (i.e. the background of the margins, legend, and plotting
+area will be white).
+.SH "GRAPH OPERATIONS"
+.TP
+\fIpathName \fBaxis \fIoperation \fR?\fIarg\fR?...
+See the
+.SB "AXIS COMPONENTS"
+section.
+.TP
+\fIpathName \fBbar \fIelemName \fR?\fIoption value\fR?...
+Creates a new barchart element \fIelemName\fR. It's an
+error if an element \fIelemName\fR already exists.
+See the manual for \fBbarchart\fR for details about
+what \fIoption\fR and \fIvalue\fR pairs are valid.
+.TP
+\fIpathName \fBcget\fR \fIoption\fR
+Returns the current value of the configuration option given by
+\fIoption\fR. \fIOption\fR may be any option described
+below for the \fBconfigure\fR operation.
+.TP
+\fIpathName \fBconfigure \fR?\fIoption value\fR?...
+Queries or modifies the configuration options of the graph. If
+\fIoption\fR isn't specified, a list describing the current
+options for \fIpathName\fR is returned. If \fIoption\fR is specified,
+but not \fIvalue\fR, then a list describing \fIoption\fR is returned.
+If one or more \fIoption\fR and \fIvalue\fR pairs are specified, then
+for each pair, the option \fIoption\fR is set to \fIvalue\fR.
+The following options are valid.
+.RS
+.TP
+\fB\-aspect \fIwidth/height\fR
+Force a fixed aspect ratio of \fIwidth/height\fR, a floating point number.
+.TP
+\fB\-background \fIcolor\fR
+Sets the background color. This includes the margins and
+legend, but not the plotting area.
+.TP
+\fB\-borderwidth \fIpixels\fR
+Sets the width of the 3\-D border around the outside edge of the widget. The
+\fB\-relief\fR option determines if the border is to be drawn. The
+default is \f(CW2\fR.
+.TP
+\fB\-bottommargin \fIpixels\fR
+If non-zero, overrides the computed size of the margin extending
+below the X\-coordinate axis.
+If \fIpixels\fR is \f(CW0\fR, the automatically computed size is used.
+The default is \f(CW0\fR.
+.TP
+\fB\-bufferelements \fIboolean\fR
+Indicates whether an internal pixmap to buffer the display of data
+elements should be used. If \fIboolean\fR is true, data elements are
+drawn to an internal pixmap. This option is especially useful when
+the graph is redrawn frequently while the remains data unchanged (for
+example, moving a marker across the plot). See the
+.SB "SPEED TIPS"
+section.
+The default is \f(CW1\fR.
+.TP
+\fB\-cursor \fIcursor\fR
+Specifies the widget's cursor. The default cursor is \f(CWcrosshair\fR.
+.TP
+\fB\-font \fIfontName\fR
+Specifies the font of the graph title. The default is
+\f(CW*-Helvetica-Bold-R-Normal-*-18-180-*\fR.
+.TP
+\fB\-halo \fIpixels\fR
+Specifies a maximum distance to consider when searching for the
+closest data point (see the element's \fBclosest\fR operation below).
+Data points further than \fIpixels\fR away are ignored. The default is
+\f(CW0.5i\fR.
+.TP
+\fB\-height \fIpixels\fR
+Specifies the requested height of widget. The default is
+\f(CW4i\fR.
+.TP
+\fB\-invertxy \fIboolean\fR
+Indicates whether the placement X\-axis and Y\-axis should be inverted. If
+\fIboolean\fR is true, the X and Y axes are swapped. The default is
+\f(CW0\fR.
+.TP
+\fB\-justify \fIjustify\fR
+Specifies how the title should be justified. This matters only when
+the title contains more than one line of text. \fIJustify\fR must be
+\f(CWleft\fR, \f(CWright\fR, or \f(CWcenter\fR. The default is
+\f(CWcenter\fR.
+.TP
+\fB\-leftmargin \fIpixels\fR
+If non-zero, overrides the computed size of the margin extending
+from the left edge of the window to the Y\-coordinate axis.
+If \fIpixels\fR is \f(CW0\fR, the automatically computed size is used.
+The default is \f(CW0\fR.
+.TP
+\fB\-plotbackground \fIcolor\fR
+Specifies the background color of the plotting area. The default is
+\f(CWwhite\fR.
+.TP
+\fB\-plotborderwidth \fIpixels\fR
+Sets the width of the 3-D border around the plotting area. The
+\fB\-plotrelief\fR option determines if a border is drawn. The
+default is \f(CW2\fR.
+.TP
+\fB\-plotpadx \fIpad\fR
+Sets the amount of padding to be added to the left and right sides of
+the plotting area. \fIPad\fR can be a list of one or two screen
+distances. If \fIpad\fR has two elements, the left side of the
+plotting area entry is padded by the first distance and the right side
+by the second. If \fIpad\fR is just one distance, both the left and
+right sides are padded evenly. The default is \f(CW8\fR.
+.TP
+\fB\-plotpady \fIpad\fR
+Sets the amount of padding to be added to the top and bottom of the
+plotting area. \fIPad\fR can be a list of one or two screen
+distances. If \fIpad\fR has two elements, the top of the plotting
+area is padded by the first distance and the bottom by the second. If
+\fIpad\fR is just one distance, both the top and bottom are padded
+evenly. The default is \f(CW8\fR.
+.TP
+\fB\-plotrelief \fIrelief\fR
+Specifies the 3-D effect for the plotting area. \fIRelief\fR
+specifies how the interior of the plotting area should appear relative
+to rest of the graph; for example, \f(CWraised\fR means the plot should
+appear to protrude from the graph, relative to the surface of the
+graph. The default is \f(CWsunken\fR.
+.TP
+\fB\-relief \fIrelief\fR
+Specifies the 3-D effect for the graph widget. \fIRelief\fR
+specifies how the graph should appear relative to widget it is packed
+into; for example, \f(CWraised\fR means the graph should
+appear to protrude. The default is \f(CWflat\fR.
+.TP
+\fB\-rightmargin \fIpixels\fR
+If non-zero, overrides the computed size of the margin extending
+from the plotting area to the right edge of
+the window. By default, the legend is drawn in this margin.
+If \fIpixels\fR is \f(CW0\fR, the automatically computed size is used.
+The default is \f(CW0\fR.
+.TP
+\fB\-takefocus\fR \fIfocus\fR
+Provides information used when moving the focus from window to window
+via keyboard traversal (e.g., Tab and Shift-Tab). If \fIfocus\fR is
+\f(CW0\fR, this means that this window should be skipped entirely during
+keyboard traversal. \f(CW1\fR means that the this window should always
+receive the input focus. An empty value means that the traversal
+scripts make the decision whether to focus on the window.
+The default is \f(CW""\fR.
+.TP
+\fB\-tile \fIimage\fR
+Specifies a tiled background for the widget. If \fIimage\fR isn't
+\f(CW""\fR, the background is tiled using \fIimage\fR.
+Otherwise, the normal background color is drawn (see the
+\fB\-background\fR option). \fIImage\fR must be an image created
+using the Tk \fBimage\fR command. The default is \f(CW""\fR.
+.TP
+\fB\-title \fItext\fR
+Sets the title to \fItext\fR. If \fItext\fR is \f(CW""\fR,
+no title will be displayed.
+.TP
+\fB\-topmargin \fIpixels\fR
+If non-zero, overrides the computed size of the margin above the x2
+axis. If \fIpixels\fR is \f(CW0\fR, the automatically computed size
+is used. The default is \f(CW0\fR.
+.TP
+\fB\-width \fIpixels\fR
+Specifies the requested width of the widget. The default is
+\f(CW5i\fR.
+.RE
+.TP
+\fIpathName \fBcrosshairs \fIoperation \fR?\fIarg\fR?
+See the
+.SB "CROSSHAIRS COMPONENT"
+section.
+.TP
+\fIpathName \fBelement \fIoperation \fR?\fIarg\fR?...
+See the
+.SB "ELEMENT COMPONENTS"
+section.
+.TP
+\fIpathName \fBextents \fIitem\fR
+Returns the size of a particular item in the graph. \fIItem\fR must
+be either \f(CWleftmargin\fR, \f(CWrightmargin\fR, \f(CWtopmargin\fR,
+\f(CWbottommargin\fR, \f(CWplotwidth\fR, or \f(CWplotheight\fR.
+.TP
+\fIpathName \fBgrid \fIoperation \fR?\fIarg\fR?...
+See the
+.SB "GRID COMPONENT"
+section.
+.TP
+\fIpathName \fBinvtransform \fIwinX winY\fR
+Performs an inverse coordinate transformation, mapping window
+coordinates back to graph coordinates, using the standard X\-axis and Y\-axis.
+Returns a list of containing the X-Y graph coordinates.
+.TP
+\fIpathName \fBinside \fIx y\fR
+Returns \f(CW1\fR is the designated screen coordinate (\fIx\fR and \fIy\fR)
+is inside the plotting area and \f(CW0\fR otherwise.
+.TP
+\fIpathName \fBlegend \fIoperation \fR?\fIarg\fR?...
+See the
+.SB "LEGEND COMPONENT"
+section.
+.TP
+\fIpathName \fBline\fB operation arg\fR...
+The operation is the same as \fBelement\fR.
+.TP
+\fIpathName \fBmarker \fIoperation \fR?\fIarg\fR?...
+See the
+.SB "MARKER COMPONENTS"
+section.
+.TP
+\fIpathName \fBpostscript \fIoperation \fR?\fIarg\fR?...
+See the
+.SB "POSTSCRIPT COMPONENT"
+section.
+.TP
+\fIpathName \fBsnap \fR?\fIswitches\fR? \fIoutputName\fR
+Takes a snapshot of the graph, saving the output in \fIoutputName\fR.
+The following switches are available.
+.RS
+.TP 1i
+\fB\-format\fR \fIformat\fR
+Specifies how the snapshot is output. \fIFormat\fR may be one of
+the following listed below. The default is \f(CWphoto\fR.
+.RS
+.TP
+\f(CWphoto\fR
+Saves a Tk photo image. \fIOutputName\fR represents the name of a
+Tk photo image that must already have been created.
+.TP
+\f(CWwmf\fR
+Saves an Aldus Placeable Metafile. \fIOutputName\fR represents the
+filename where the metafile is written. If \fIoutputName\fR is
+\f(CWCLIPBOARD\fR, then output is written directly to the Windows
+clipboard. This format is available only under Microsoft Windows.
+.TP
+\f(CWemf\fR
+Saves an Enhanced Metafile. \fIOutputName\fR represents the filename
+where the metafile is written. If \fIoutputName\fR is
+\f(CWCLIPBOARD\fR, then output is written directly to the Windows
+clipboard. This format is available only under Microsoft Windows.
+.RE
+.TP 1i
+\fB\-height\fR \fIsize\fR
+Specifies the height of the graph. \fISize\fR is a screen distance.
+The graph will be redrawn using this dimension, rather than its
+current window height.
+.TP 1i
+\fB\-width\fR \fIsize\fR
+Specifies the width of the graph. \fISize\fR is a screen distance.
+The graph will be redrawn using this dimension, rather than its
+current window width.
+.RE
+.TP
+\fIpathName \fBtransform \fIx y\fR
+Performs a coordinate transformation, mapping graph coordinates to
+window coordinates, using the standard X\-axis and Y\-axis.
+Returns a list containing the X\-Y screen coordinates.
+.TP
+\fIpathName \fBxaxis \fIoperation\fR ?\fIarg\fR?...
+.TP
+\fIpathName \fBx2axis \fIoperation\fR ?\fIarg\fR?...
+.TP
+\fIpathName \fByaxis \fIoperation\fR ?\fIarg\fR?...
+.TP
+\fIpathName \fBy2axis \fIoperation\fR ?\fIarg\fR?...
+See the
+.SB "AXIS COMPONENTS"
+section.
+.SH "GRAPH COMPONENTS"
+A graph is composed of several components: coordinate axes, data
+elements, legend, grid, cross hairs, postscript, and annotation
+markers. Instead of one big set of configuration options and
+operations, the graph is partitioned, where each component has its own
+configuration options and operations that specifically control that
+aspect or part of the graph.
+.SS "AXIS COMPONENTS"
+Four coordinate axes are automatically created: two X\-coordinate axes
+(\f(CWx\fR and \f(CWx2\fR) and two Y\-coordinate axes (\f(CWy\fR, and
+\f(CWy2\fR). By default, the axis \f(CWx\fR is located in the bottom
+margin, \f(CWy\fR in the left margin, \f(CWx2\fR in the top margin, and
+\f(CWy2\fR in the right margin.
+.PP
+An axis consists of the axis line, title, major and minor ticks, and
+tick labels. Major ticks are drawn at uniform intervals along the
+axis. Each tick is labeled with its coordinate value. Minor ticks
+are drawn at uniform intervals within major ticks.
+.PP
+The range of the axis controls what region of data is plotted.
+Data points outside the minimum and maximum limits of the axis are
+not plotted. By default, the minimum and maximum limits are
+determined from the data, but you can reset either limit.
+.PP
+You can have several axes. To create an axis, invoke
+the axis component and its create operation.
+.CS
+# Create a new axis called "tempAxis"
+\&.g axis create tempAxis
+.CE
+You map data elements to an axis using the element's \-mapy and \-mapx
+configuration options. They specify the coordinate axes an element
+is mapped onto.
+.CS
+# Now map the tempAxis data to this axis.
+\&.g element create "e1" \-xdata $x \-ydata $y \-mapy tempAxis
+.CE
+Any number of axes can be displayed simultaneously. They are drawn in
+the margins surrounding the plotting area. The default axes \f(CWx\fR
+and \f(CWy\fR are drawn in the bottom and left margins. The axes
+\f(CWx2\fR and \f(CWy2\fR are drawn in top and right margins. By
+default, only \f(CWx\fR and \f(CWy\fR are shown. Note that the axes
+can have different scales.
+.PP
+To display a different axis or more than one axis, you invoke one of
+the following components: \fBxaxis\fR, \fByaxis\fR, \fBx2axis\fR, and
+\fBy2axis\fR. Each component has a \fBuse\fR operation that
+designates the axis (or axes) to be drawn in that corresponding
+margin: \fBxaxis\fR in the bottom, \fByaxis\fR in the left,
+\fBx2axis\fR in the top, and \fBy2axis\fR in the right.
+.CS
+# Display the axis tempAxis in the left margin.
+\&.g yaxis use tempAxis
+.CE
+The \fBuse\fR operation takes a list of axis names as its last
+argument. This is the list of axes to be drawn in this margin.
+.PP
+You can configure axes in many ways. The axis scale can be linear or
+logarithmic. The values along the axis can either monotonically
+increase or decrease. If you need custom tick labels, you can specify
+a Tcl procedure to format the label any way you wish. You can control
+how ticks are drawn, by changing the major tick interval or the number
+of minor ticks. You can define non-uniform tick intervals, such as
+for time-series plots.
+.PP
+.TP
+\fIpathName \fBaxis bind \fItagName\fR ?\fIsequence\fR? ?\fIcommand\fR?
+Associates \fIcommand\fR with \fItagName\fR such that whenever the
+event sequence given by \fIsequence\fR occurs for an axis with this
+tag, \fIcommand\fR will be invoked. The syntax is similar to the
+\fBbind\fR command except that it operates on graph axes, rather
+than widgets. See the \fBbind\fR manual entry for
+complete details on \fIsequence\fR and the substitutions performed on
+\fIcommand\fR before invoking it.
+.sp
+If all arguments are specified then a new binding is created, replacing
+any existing binding for the same \fIsequence\fR and \fItagName\fR.
+If the first character of \fIcommand\fR is \f(CW+\fR then \fIcommand\fR
+augments an existing binding rather than replacing it.
+If no \fIcommand\fR argument is provided then the command currently
+associated with \fItagName\fR and \fIsequence\fR (it's an error occurs
+if there's no such binding) is returned. If both \fIcommand\fR and
+\fIsequence\fR are missing then a list of all the event sequences for
+which bindings have been defined for \fItagName\fR.
+.TP
+\fIpathName \fBaxis \fBcget \fIaxisName \fIoption\fR
+Returns the current value of the option given by \fIoption\fR for
+\fIaxisName\fR. \fIOption\fR may be any option described below
+for the axis \fBconfigure\fR operation.
+.TP
+\fIpathName \fBaxis \fBconfigure \fIaxisName \fR?\fIaxisName\fR?... ?\fIoption value\fR?...
+Queries or modifies the configuration options of \fIaxisName\fR.
+Several axes can be changed. If \fIoption\fR isn't specified, a list
+describing all the current options for \fIaxisName\fR is returned. If
+\fIoption\fR is specified, but not \fIvalue\fR, then a list describing
+\fIoption\fR is returned. If one or more \fIoption\fR and \fIvalue\fR
+pairs are specified, then for each pair, the axis option \fIoption\fR
+is set to \fIvalue\fR. The following options are valid for axes.
+.RS
+.TP
+\fB\-bindtags \fItagList\fR
+Specifies the binding tags for the axis. \fITagList\fR is a list
+of binding tag names. The tags and their order will determine how
+events for axes are handled. Each tag in the list matching the current event
+sequence will have its Tcl command executed. Implicitly the name of
+the element is always the first tag in the list. The default value is
+\f(CWall\fR.
+.TP
+\fB\-color \fIcolor\fR
+Sets the color of the axis and tick labels.
+The default is \f(CWblack\fR.
+.TP
+\fB\-descending \fIboolean\fR
+Indicates whether the values along the axis are monotonically increasing or
+decreasing. If \fIboolean\fR is true, the axis values will be
+decreasing. The default is \f(CW0\fR.
+.TP
+\fB\-hide \fIboolean\fR
+Indicates if the axis is displayed. If \fIboolean\fR is false the axis
+will be displayed. Any element mapped to the axis is displayed regardless.
+The default value is \f(CW0\fR.
+.TP
+\fB\-justify \fIjustify\fR
+Specifies how the axis title should be justified. This matters only
+when the axis title contains more than one line of text. \fIJustify\fR
+must be \f(CWleft\fR, \f(CWright\fR, or \f(CWcenter\fR. The default is
+\f(CWcenter\fR.
+.TP
+\fB\-limits \fIformatStr\fR
+Specifies a printf-like description to format the minimum and maximum
+limits of the axis. The limits are displayed at the top/bottom or
+left/right sides of the plotting area. \fIFormatStr\fR is a list of
+one or two format descriptions. If one description is supplied, both
+the minimum and maximum limits are formatted in the same way. If two,
+the first designates the format for the minimum limit, the second for
+the maximum. If \f(CW""\fR is given as either description, then
+the that limit will not be displayed. The default is \f(CW""\fR.
+.TP
+\fB\-linewidth \fIpixels\fR
+Sets the width of the axis and tick lines. The default is \f(CW1\fR
+pixel.
+.TP
+\fB\-logscale \fIboolean\fR
+Indicates whether the scale of the axis is logarithmic or linear. If
+\fIboolean\fR is true, the axis is logarithmic. The default scale is
+linear.
+.TP
+\fB\-loose \fIboolean\fR
+Indicates whether the limits of the axis should fit the data points tightly,
+at the outermost data points, or loosely, at the outer tick intervals.
+If the axis limit is set with the -min or -max option, the axes are
+displayed tightly.
+If \fIboolean\fR is true, the axis range is "loose".
+The default is \f(CW0\fR.
+.TP
+\fB\-majorticks \fImajorList\fR
+Specifies where to display major axis ticks. You can use this option
+to display ticks at non-uniform intervals. \fIMajorList\fR is a list
+of axis coordinates designating the location of major ticks. No
+minor ticks are drawn. If \fImajorList\fR is \f(CW""\fR,
+major ticks will be automatically computed. The default is \f(CW""\fR.
+.TP
+\fB\-max \fIvalue\fR
+Sets the maximum limit of \fIaxisName\fR. Any data point greater
+than \fIvalue\fR is not displayed. If \fIvalue\fR is \f(CW""\fR,
+the maximum limit is calculated using the largest data value.
+The default is \f(CW""\fR.
+.TP
+\fB\-min \fIvalue\fR
+Sets the minimum limit of \fIaxisName\fR. Any data point less than
+\fIvalue\fR is not displayed. If \fIvalue\fR is \f(CW""\fR,
+the minimum limit is calculated using the smallest data value.
+The default is \f(CW""\fR.
+.TP
+\fB\-minorticks \fIminorList\fR
+Specifies where to display minor axis ticks. You can use this option
+to display minor ticks at non-uniform intervals. \fIMinorList\fR is a
+list of real values, ranging from 0.0 to 1.0, designating the placement of
+a minor tick. No minor ticks are drawn if the \fB\-majortick\fR
+option is also set. If \fIminorList\fR is \f(CW""\fR, minor ticks will
+be automatically computed. The default is \f(CW""\fR.
+.TP
+\fB\-rotate \fItheta\fR
+Specifies the how many degrees to rotate the axis tick labels.
+\fITheta\fR is a real value representing the number of degrees
+to rotate the tick labels. The default is \f(CW0.0\fR degrees.
+.TP
+\fB\-scrollcommand \fIcommand\fR
+Specify the prefix for a command used to communicate with scrollbars
+for this axis, such as \fI.sbar set\fP.
+.TP
+\fB\-scrollmax \fIvalue\fR
+Sets the maximum limit of the axis scroll region. If \fIvalue\fR is
+\f(CW""\fR, the maximum limit is calculated using the largest data
+value. The default is \f(CW""\fR.
+.TP
+\fB\-scrollmin \fIvalue\fR
+Sets the minimum limit of axis scroll region. If \fIvalue\fR is
+\f(CW""\fR, the minimum limit is calculated using the smallest data
+value. The default is \f(CW""\fR.
+.TP
+\fB\-showticks \fIboolean\fR
+Indicates whether axis ticks should be drawn. If \fIboolean\fR is
+true, ticks are drawn. If false, only the
+axis line is drawn. The default is \f(CW1\fR.
+.TP
+\fB\-stepsize \fIvalue\fR
+Specifies the interval between major axis ticks. If \fIvalue\fR isn't
+a valid interval (must be less than the axis range),
+the request is ignored and the step size is automatically calculated.
+.TP
+\fB\-subdivisions \fInumber\fR
+Indicates how many minor axis ticks are
+to be drawn. For example, if \fInumber\fR is two, only one minor
+tick is drawn. If \fInumber\fR is one, no minor ticks are
+displayed. The default is \f(CW2\fR.
+.TP
+\fB\-tickfont \fIfontName\fR
+Specifies the font for axis tick labels. The default is
+\f(CW*-Courier-Bold-R-Normal-*-100-*\fR.
+.TP
+\fB\-tickformat\fR \fIformatStr\fR
+Specifies a printf-like description to format teh axis
+tick labels. You can get the standard tick labels again by
+setting \fIformatStr\fR to \f(CW""\fR. The default is \f(CW""\fR.
+.TP
+\fB\-tickformatcommand\fR, \fB\-command \fIprefix\fR
+Specifies a Tcl command to be invoked when formatting the axis tick
+labels. \fIPrefix\fR is a string containing the name of a Tcl proc and
+any extra arguments for the procedure. This command is invoked for each
+major tick on the axis. Two additional arguments are passed to the
+procedure: the pathname of the widget and the current the numeric
+value of the tick. The procedure returns the formatted tick label. If
+\f(CW""\fR is returned, no label will appear next to the tick. You can
+get the standard tick labels again by setting \fIprefix\fR to
+\f(CW""\fR. The default is \f(CW""\fR.
+.sp 1
+The numeric value for the tick might change when using the
+\fB\-logscale\fR and \fB\-tickformat\fR options.
+.sp 1
+Please note that this procedure is invoked while the graph is redrawn.
+You may query configuration options. But do not them, because this
+can have unexpected results.
+.TP
+\fB\-ticklength \fIpixels\fR
+Sets the length of major and minor ticks (minor ticks are half the
+length of major ticks). If \fIpixels\fR is less than zero, the axis
+will be inverted with ticks drawn pointing towards the plot. The
+default is \f(CW0.1i\fR.
+.TP
+\fB\-title \fItext\fR
+Sets the title of the axis. If \fItext\fR is
+\f(CW""\fR, no axis title will be displayed.
+.TP
+\fB\-titlealternate \fIboolean\fR
+Indicates to display the axis title in its alternate location.
+Normally the axis title is centered along the axis. This option
+places the axis either to the right (horizontal axes) or above
+(vertical axes) the axis. The default is \f(CW0\fR.
+.TP
+\fB\-titlecolor \fIcolor\fR
+Sets the color of the axis title. The default is \f(CWblack\fR.
+.TP
+\fB\-titlefont \fIfontName\fR
+Specifies the font for axis title. The default is
+\f(CW*-Helvetica-Bold-R-Normal-*-14-140-*\fR.
+.PP
+Axis configuration options may be also be set by the \fBoption\fR
+command. The resource class is \f(CWAxis\fR. The resource names
+are the names of the axes (such as \f(CWx\fR or \f(CWx2\fR).
+.CS
+option add *Graph.Axis.Color blue
+option add *Graph.x.LogScale true
+option add *Graph.x2.LogScale false
+.CE
+.RE
+.TP
+\fIpathName \fBaxis \fBcreate \fIaxisName \fR?\fIoption value\fR?...
+Creates a new axis by the name \fIaxisName\fR. No axis by the same
+name can already exist. \fIOption\fR and \fIvalue\fR are described
+in above in the axis \fBconfigure\fR operation.
+.TP
+\fIpathName \fBaxis \fBdelete \fR?\fIaxisName\fR?...
+Deletes the named axes. An axis is not really
+deleted until it is not longer in use, so it's safe to delete
+axes mapped to elements.
+.TP
+\fIpathName \fBaxis invtransform \fIaxisName value\fR
+Performs the inverse transformation, changing the screen coordinate
+\fIvalue\fR to a graph coordinate, mapping the value mapped to
+\fIaxisName\fR. Returns the graph coordinate.
+.TP
+\fIpathName \fBaxis limits \fIaxisName\fR
+Returns a list of the minimum and maximum limits for \fIaxisName\fR. The order
+of the list is \f(CWmin max\fR.
+.TP
+\fIpathName \fBaxis names \fR?\fIpattern\fR?...
+Returns a list of axes matching zero or more patterns. If no
+\fIpattern\fR argument is give, the names of all axes are returned.
+.TP
+\fIpathName \fBaxis transform \fIaxisName value\fR
+Transforms the coordinate \fIvalue\fR to a screen coordinate by mapping
+the it to \fIaxisName\fR. Returns the transformed screen coordinate.
+.TP
+\fIpathName \fBaxis view \fIaxisName\fR
+Change the viewable area of this axis. Use as an argument to a scrollbar's "\fI\-command\fR".
+.PP
+The default axes are \f(CWx\fR, \f(CWy\fR, \f(CWx2\fR, and \f(CWy2\fR.
+But you can display more than four axes simultaneously. You can also
+swap in a different axis with \fBuse\fR operation of the special axis
+components: \fBxaxis\fR, \fBx2axis\fR, \fByaxis\fR, and \fBy2axis\fR.
+.CS
+\&.g create axis temp
+\&.g create axis time
+\&...
+\&.g xaxis use temp
+\&.g yaxis use time
+.CE
+Only the axes specified for use are displayed on the screen.
+.PP
+The \fBxaxis\fR, \fBx2axis\fR, \fByaxis\fR, and \fBy2axis\fR
+components operate on an axis location rather than a specific axis
+like the more general \fBaxis\fR component does. They implicitly
+control the axis that is currently using to that location. By
+default, \fBxaxis\fR uses the \f(CWx\fR axis, \fByaxis\fR uses
+\f(CWy\fR, \fBx2axis\fR uses \f(CWx2\fR, and \fBy2axis\fR uses
+\f(CWy2\fR. When more than one axis is displayed in a margin, it
+represents the first axis displayed.
+.PP
+The following operations are available for axes. They mirror exactly
+the operations of the \fBaxis\fR component. The \fIaxis\fR argument
+must be \fBxaxis\fR, \fBx2axis\fR, \fByaxis\fR, or \fBy2axis\fR. This
+feature is deprecated since more than one axis can now be used a
+margin. You should only use the \fBxaxis\fR, \fBx2axis\fR,
+\fByaxis\fR, and \fBy2axis\fR components with the \fBuse\fR operation.
+For all other operations, use the general \fBaxis\fR component
+instead.
+.TP
+\fIpathName \fIaxis \fBcget \fIoption\fR
+.TP
+\fIpathName \fIaxis \fBconfigure \fR?\fIoption value\fR?...
+.TP
+\fIpathName \fIaxis\fB invtransform \fIvalue\fR
+.TP
+\fIpathName \fIaxis \fBlimits\fR
+.TP
+\fIpathName \fIaxis\fB transform \fIvalue\fR
+.TP
+\fIpathName \fIaxis\fB use \fR?\fIaxisName\fR?
+Designates the axis \fIaxisName\fR is to be displayed at this
+location. \fIAxisName\fR can not be already in use at another location.
+This command returns the name of the axis currently using this location.
+.SS "CROSSHAIRS COMPONENT"
+Cross hairs consist of two intersecting lines (one vertical and one horizontal)
+drawn completely across the plotting area. They are used to position
+the mouse in relation to the coordinate axes. Cross hairs differ from line
+markers in that they are implemented using XOR drawing primitives.
+This means that they can be quickly drawn and erased without redrawing
+the entire graph.
+.PP
+The following operations are available for cross hairs:
+.TP
+\fIpathName \fBcrosshairs cget \fIoption\fR
+Returns the current value of the cross hairs configuration option
+given by \fIoption\fR. \fIOption\fR may be any option
+described below for the cross hairs \fBconfigure\fR operation.
+.TP
+\fIpathName \fBcrosshairs configure \fR?\fIoption value\fR?...
+Queries or modifies the configuration options of the cross hairs. If
+\fIoption\fR isn't specified, a list describing all the current
+options for the cross hairs is returned. If \fIoption\fR is specified,
+but not \fIvalue\fR, then a list describing \fIoption\fR is returned.
+If one or more \fIoption\fR and \fIvalue\fR pairs are specified, then
+for each pair, the cross hairs option \fIoption\fR is set to
+\fIvalue\fR.
+The following options are available for cross hairs.
+.RS
+.TP
+\fB\-color \fIcolor\fR
+Sets the color of the cross hairs. The default is \f(CWblack\fR.
+.TP
+\fB\-dashes \fIdashList\fR
+Sets the dash style of the cross hairs. \fIDashList\fR is a list of up
+to 11 numbers that alternately represent the lengths of the dashes
+and gaps on the cross hair lines. Each number must be between 1 and
+255. If \fIdashList\fR is \f(CW""\fR, the cross hairs will be solid
+lines.
+.TP
+\fB\-hide \fIboolean\fR
+Indicates whether cross hairs are drawn. If \fIboolean\fR is true,
+cross hairs are not drawn. The default is \f(CWyes\fR.
+.TP
+\fB\-linewidth \fIpixels\fR
+Set the width of the cross hair lines. The default is \f(CW1\fR.
+.TP
+\fB\-position \fIpos\fR
+Specifies the screen position where the cross hairs intersect.
+\fIPos\fR must be in the form "\fI@x,y\fR", where \fIx\fR and \fIy\fR
+are the window coordinates of the intersection.
+.PP
+Cross hairs configuration options may be also be set by the
+\fBoption\fR command. The resource name and class are
+\f(CWcrosshairs\fR and \f(CWCrosshairs\fR respectively.
+.CS
+option add *Graph.Crosshairs.LineWidth 2
+option add *Graph.Crosshairs.Color red
+.CE
+.RE
+.TP
+\fIpathName \fBcrosshairs off\fR
+Turns off the cross hairs.
+.TP
+\fIpathName \fBcrosshairs on\fR
+Turns on the display of the cross hairs.
+.TP
+\fIpathName \fBcrosshairs toggle\fR
+Toggles the current state of the cross hairs, alternately mapping and
+unmapping the cross hairs.
+.SS "ELEMENT COMPONENTS"
+A data element represents a set of data. It contains x and y vectors
+containing the coordinates of the data points. Elements can be
+displayed with a symbol at each data point and lines connecting the
+points. Elements also control the appearance of the data, such as the
+symbol type, line width, color etc.
+.PP
+When new data elements are created, they are automatically added to a
+list of displayed elements. The display list controls what elements
+are drawn and in what order.
+.PP
+The following operations are available for elements.
+.TP
+\fIpathName \fBelement activate \fIelemName \fR?\fIindex\fR?...
+Specifies the data points of element \fIelemName\fR to be drawn
+using active foreground and background colors. \fIElemName\fR is the
+name of the element and \fIindex\fR is a number representing the index
+of the data point. If no indices are present then all data points
+become active.
+.TP
+\fIpathName \fBelement bind \fItagName\fR ?\fIsequence\fR? ?\fIcommand\fR?
+Associates \fIcommand\fR with \fItagName\fR such that whenever the
+event sequence given by \fIsequence\fR occurs for an element with this
+tag, \fIcommand\fR will be invoked. The syntax is similar to the
+\fBbind\fR command except that it operates on graph elements, rather
+than widgets. See the \fBbind\fR manual entry for
+complete details on \fIsequence\fR and the substitutions performed on
+\fIcommand\fR before invoking it.
+.sp
+If all arguments are specified then a new binding is created, replacing
+any existing binding for the same \fIsequence\fR and \fItagName\fR.
+If the first character of \fIcommand\fR is \f(CW+\fR then \fIcommand\fR
+augments an existing binding rather than replacing it.
+If no \fIcommand\fR argument is provided then the command currently
+associated with \fItagName\fR and \fIsequence\fR (it's an error occurs
+if there's no such binding) is returned. If both \fIcommand\fR and
+\fIsequence\fR are missing then a list of all the event sequences for
+which bindings have been defined for \fItagName\fR.
+.TP
+\fIpathName \fBelement cget \fIelemName \fIoption\fR
+Returns the current value of the element configuration option given by
+\fIoption\fR. \fIOption\fR may be any of the options described below
+for the element \fBconfigure\fR operation.
+.TP
+\fIpathName \fBelement closest \fIx y\fR ?\fIoption value\fR?... ?\fIelemName\fR?...
+Searches for the data point closest to the window coordinates \fIx\fR
+and \fIy\fR. By default, all elements are searched. Hidden elements
+(see the \fB\-hide\fR option is false) are ignored. You can limit the
+search by specifying only the elements you want to be considered.
+\fIElemName\fR must be the name of an element that can not be hidden.
+It returns a key-value list containing the name of the closest element,
+the index of the closest data point, and the graph-coordinates of the point.
+Returns \f(CW""\fR, if no data point within the threshold distance
+can be found. The following
+\fIoption\fR\-\fIvalue\fR pairs are available.
+.RS
+.TP
+\fB\-along \fIdirection\fR
+Search for the closest element using the following criteria:
+.RS
+.TP
+\f(CWx\fR
+Find closest element vertically from the given X-coordinate.
+.TP
+\f(CWy\fR
+Find the closest element horizontally from the given Y-coordinate.
+.TP
+\f(CWboth\fR
+Find the closest element for the given point (using both the X and Y
+coordinates).
+.RE
+.TP
+\fB\-halo \fIpixels\fR
+Specifies a threshold distance where selected data points are ignored.
+\fIPixels\fR is a valid screen distance, such as \f(CW2\fR or \f(CW1.2i\fR.
+If this option isn't specified, then it defaults to the value of the
+graph's \fB\-halo\fR option.
+.TP
+\fB\-interpolate \fIstring\fR
+Indicates whether to consider projections that lie along the line segments
+connecting data points when searching for the closest point.
+The default value is \f(CW0\fR. The values for \fIstring\fR are
+described below.
+.RS
+.TP 1.25i
+\f(CWno\fR
+Search only for the closest data point.
+.TP
+\f(CWyes\fR
+Search includes projections that lie along the
+line segments connecting the data points.
+.RE
+.RE
+.TP
+\fIpathName \fBelement configure \fIelemName \fR?\fIelemName\fR... ?\fIoption value\fR?...
+Queries or modifies the configuration options for elements. Several
+elements can be modified at the same time. If \fIoption\fR isn't
+specified, a list describing all the current options for
+\fIelemName\fR is returned. If \fIoption\fR is specified, but not
+\fIvalue\fR, then a list describing the option \fIoption\fR is
+returned. If one or more \fIoption\fR and \fIvalue\fR pairs are
+specified, then for each pair, the element option \fIoption\fR is set
+to \fIvalue\fR. The following options are valid for elements.
+.RS
+.TP
+\fB\-activepen \fIpenName\fR
+Specifies pen to use to draw active element. If \fIpenName\fR is
+\f(CW""\fR, no active elements will be drawn. The default is
+\f(CWactiveLine\fR.
+.TP
+\fB\-areabackground \fIcolor\fR
+Specifies the background color of the area under the curve. The
+background area color is drawn only for bitmaps (see the
+\fB\-areapattern\fR option). If \fIcolor\fR is \f(CW""\fR, the
+background is transparent. The default is \f(CWblack\fR.
+.TP
+\fB\-areaforeground \fIcolor\fR
+Specifies the foreground color of the area under the curve.
+The default is \f(CWblack\fR.
+.TP
+\fB\-areapattern \fIpattern\fR
+Specifies how to fill the area under the curve. \fIPattern\fR may be
+the name of a Tk bitmap, \f(CWsolid\fR, or \f(CW""\fR. If "solid",
+then the area under the curve is drawn with the color designated by
+the \fB\-areaforeground\fR option. If a bitmap, then the bitmap is
+stippled across the area. Here the bitmap colors are controlled by the
+\fB\-areaforeground\fR and \fB\-areabackground\fR options. If
+\fIpattern\fR is \f(CW""\fR, no filled area is drawn. The default is
+\f(CW""\fR.
+.TP
+\fB\-areatile \fIimage\fR
+Specifies the name of a Tk image to be used to tile the area under the
+curve. This option supersedes the \fB\-areapattern\fR option.
+\fIImage\fR must be a photo image. If \fIimage\fR is \f(CW""\fR, no
+tiling is performed. The default is \f(CW""\fR.
+.TP
+\fB\-bindtags \fItagList\fR
+Specifies the binding tags for the element. \fITagList\fR is a list
+of binding tag names. The tags and their order will determine how
+events are handled for elements. Each tag in the list matching the
+current event
+sequence will have its Tcl command executed. Implicitly the name of
+the element is always the first tag in the list. The default value is
+\f(CWall\fR.
+.TP
+\fB\-color \fIcolor\fR
+Sets the color of the traces connecting the data points.
+.TP
+\fB\-dashes \fIdashList\fR
+Sets the dash style of element line. \fIDashList\fR is a list of up to
+11 numbers that alternately represent the lengths of the dashes and
+gaps on the element line. Each number must be between 1 and 255. If
+\fIdashList\fR is \f(CW""\fR, the lines will be solid.
+.TP
+\fB\-data \fIcoordList\fR
+Specifies the X\-Y coordinates of the data. \fICoordList\fR is a
+list of numeric expressions representing the X\-Y coordinate pairs
+of each data point.
+.TP
+\fB\-fill \fIcolor\fR
+Sets the interior color of symbols. If \fIcolor\fR is \f(CW""\fR, then
+the interior of the symbol is transparent. If \fIcolor\fR is
+\f(CWdefcolor\fR, then the color will be the same as the \fB\-color\fR
+option. The default is \f(CWdefcolor\fR.
+.TP
+\fB\-hide \fIboolean\fR
+Indicates whether the element is displayed.
+The default is \f(CWno\fR.
+.TP
+\fB\-label \fItext\fR
+Sets the element's label in the legend. If \fItext\fR
+is \f(CW""\fR, the element will have no entry in the legend.
+The default label is the element's name.
+.TP
+\fB\-linewidth \fIpixels\fR
+Sets the width of the connecting lines between data points. If
+\fIpixels\fR is \f(CW0\fR, no connecting lines will be drawn between
+symbols. The default is \f(CW0\fR.
+.TP
+\fB\-mapx \fIxAxis\fR
+Selects the X\-axis to map the element's X\-coordinates onto.
+\fIXAxis\fR must be the name of an axis. The default is \f(CWx\fR.
+.TP
+\fB\-mapy \fIyAxis\fR
+Selects the Y\-axis to map the element's Y\-coordinates onto.
+\fIYAxis\fR must be the name of an axis. The default is \f(CWy\fR.
+.TP
+\fB\-offdash \fIcolor\fR
+Sets the color of the stripes when traces are dashed (see the
+\fB\-dashes\fR option). If \fIcolor\fR is \f(CW""\fR, then the "off"
+pixels will represent gaps instead of stripes. If \fIcolor\fR is
+\f(CWdefcolor\fR, then the color will be the same as the \fB\-color\fR
+option. The default is \f(CWdefcolor\fR.
+.TP
+\fB\-outline \fIcolor\fR
+Sets the color or the outline around each symbol. If \fIcolor\fR is
+\f(CW""\fR, then no outline is drawn. If \fIcolor\fR is \f(CWdefcolor\fR,
+then the color will be the same as the \fB\-color\fR option. The
+default is \f(CWdefcolor\fR.
+.TP
+\fB\-pen \fIpenname\fR
+Set the pen to use for this element.
+.TP
+\fB\-outlinewidth \fIpixels\fR
+Sets the width of the outline bordering each symbol. If \fIpixels\fR
+is \f(CW0\fR, no outline will be drawn. The default is \f(CW1\fR.
+.TP
+\fB\-pixels \fIpixels\fR
+Sets the size of symbols. If \fIpixels\fR is \f(CW0\fR, no symbols will
+be drawn. The default is \f(CW0.125i\fR.
+.TP
+\fB\-scalesymbols \fIboolean\fR
+If \fIboolean\fR is true, the size of the symbols
+drawn for \fIelemName\fR will change with scale of the X\-axis and Y\-axis.
+At the time this option is set, the current ranges of the axes are
+saved as the normalized scales (i.e scale factor is 1.0) and the
+element is drawn at its designated size (see the \fB\-pixels\fR
+option). As the scale of the axes change, the symbol will be scaled
+according to the smaller of the X\-axis and Y\-axis scales. If \fIboolean\fR
+is false, the element's symbols are drawn at the designated size,
+regardless of axis scales. The default is \f(CW0\fR.
+.TP
+\fB\-smooth \fIsmooth\fR
+Specifies how connecting line segments are drawn between data points.
+\fISmooth\fR can be either \f(CWlinear\fR, \f(CWstep\fR, \f(CWnatural\fR, or
+\f(CWquadratic\fR. If \fIsmooth\fR is \f(CWlinear\fR, a single line
+segment is drawn, connecting both data points. When \fIsmooth\fR is
+\f(CWstep\fR, two line segments are drawn. The first is a horizontal
+line segment that steps the next X\-coordinate. The second is a
+vertical line, moving to the next Y\-coordinate. Both \fInatural\fR and
+\fIquadratic\fR generate multiple segments between data points. If
+\fInatural\fR, the segments are generated using a cubic spline. If
+\fIquadratic\fR, a quadratic spline is used. The default is
+\fIlinear\fR.
+.TP
+\fB\-styles \fIstyleList\fR
+Specifies what pen to use based on the range of weights given.
+\fIStyleList\fR is a list of style specifications. Each style
+specification, in turn, is a list consisting of a pen name, and
+optionally a minimum and maximum range. Data points whose weight (see
+the \fB\-weight\fR option) falls in this range, are drawn with this
+pen. If no range is specified it defaults to the index of the pen in
+the list. Note that this affects only symbol attributes. Line
+attributes, such as line width, dashes, etc. are ignored.
+.TP
+\fB\-symbol \fIsymbol\fR
+Specifies the symbol for data points. \fISymbol\fR can be either
+\f(CWsquare\fR, \f(CWcircle\fR, \f(CWdiamond\fR, \f(CWplus\fR, \f(CWcross\fR,
+\f(CWsplus\fR, \f(CWscross\fR, \f(CWtriangle\fR, \f(CW""\fR (where no symbol
+is drawn), or a bitmap. Bitmaps are specified as "\fIsource\fR
+?\fImask\fR?", where \fIsource\fR is the name of the bitmap, and
+\fImask\fR is the bitmap's optional mask. The default is
+\f(CWcircle\fR.
+.TP
+\fB\-trace \fIdirection\fR
+Indicates whether connecting lines between data points (whose
+X\-coordinate values are either increasing or decreasing) are drawn.
+\fIDirection\fR
+must be \f(CWincreasing\fR, \f(CWdecreasing\fR, or \f(CWboth\fR. For
+example, if \fIdirection\fR is \f(CWincreasing\fR, connecting lines will
+be drawn only between those data points where X\-coordinate values are
+monotonically increasing. If \fIdirection\fR is \f(CWboth\fR,
+connecting lines will be draw between all data points. The default is
+\f(CWboth\fR.
+.TP
+\fB\-weights \fIwVec\fR
+Specifies the weights of the individual data points. This,
+with the list pen styles (see the \fB\-styles\fR option),
+controls how data points are drawn. \fIWVec\fR is the name of a BLT
+vector or a list of numeric expressions representing the weights for
+each data point.
+.TP
+\fB\-xdata \fIxVec\fR
+Specifies the X\-coordinates of the data. \fIXVec\fR is the name of
+a BLT vector or a list of numeric expressions.
+.TP
+\fB\-ydata \fIyVec\fR
+Specifies the Y\-coordinates of the data. \fIYVec\fR is the name of
+a BLT vector or a list of numeric expressions.
+.PP
+Element configuration options may also be set by the \fBoption\fR
+command. The resource class is \f(CWElement\fR. The resource name is
+the name of the element.
+.CS
+option add *Graph.Element.symbol line
+option add *Graph.e1.symbol line
+.CE
+.RE
+.TP
+\fIpathName \fBelement create \fIelemName\fR ?\fIoption value\fR?...
+Creates a new element \fIelemName\fR. It's an error is
+an element \fIelemName\fR already exists. If
+additional arguments are present, they specify options valid for
+the element \fBconfigure\fR operation.
+.TP
+\fIpathName \fBelement deactivate \fIelemName\fR ?\fIelemName\fR?...
+Deactivates all the elements matching \fIpattern\fR.
+Elements whose names match any of the patterns given are redrawn using
+their normal colors.
+.TP
+\fIpathName \fBelement delete\fR ?\fIelemName\fR?...
+Deletes all the named elements. The graph is automatically redrawn.
+.TP
+\fIpathName \fBelement exists \fIelemName\fR
+Returns \f(CW1\fR if an element \fIelemName\fR currently exists and
+\f(CW0\fR otherwise.
+.TP
+\fIpathName \fBelement names \fR?\fIpattern\fR?...
+Returns the elements matching one or more pattern. If no
+\fIpattern\fR is given, the names of all elements is returned.
+.TP
+\fIpathName \fBelement show\fR ?\fInameList\fR?
+Queries or modifies the element display list. The element display
+list designates the elements drawn and in what
+order. \fINameList\fR is a list of elements to be displayed in the
+order they are named. If there is no \fInameList\fR argument,
+the current display list is returned.
+.TP
+\fIpathName \fBelement type\fR \fIelemName\fR
+Returns the type of \fIelemName\fR.
+If the element is a bar element, the commands returns the string
+\f(CW"bar"\fR, otherwise it returns \f(CW"line"\fR.
+.CE
+.SS "GRID COMPONENT"
+Grid lines extend from the major and minor ticks of each axis
+horizontally or vertically across the plotting area. The following
+operations are available for grid lines.
+.TP
+\fIpathName \fBgrid cget \fIoption\fR
+Returns the current value of the grid line configuration option given by
+\fIoption\fR. \fIOption\fR may be any option described below
+for the grid \fBconfigure\fR operation.
+.TP
+\fIpathName \fBgrid configure\fR ?\fIoption value\fR?...
+Queries or modifies the configuration options for grid lines. If
+\fIoption\fR isn't specified, a list describing all the current
+grid options for \fIpathName\fR is returned. If \fIoption\fR is specified,
+but not \fIvalue\fR, then a list describing \fIoption\fR is
+returned. If one or more \fIoption\fR and \fIvalue\fR pairs are
+specified, then for each pair, the grid line option \fIoption\fR is set to
+\fIvalue\fR. The following options are valid for grid lines.
+.RS
+.TP
+\fB\-color \fIcolor\fR
+Sets the color of the grid lines. The default is \f(CWblack\fR.
+.TP
+\fB\-dashes \fIdashList\fR
+Sets the dash style of the grid lines. \fIDashList\fR is a list of up
+to 11 numbers that alternately represent the lengths of the dashes
+and gaps on the grid lines. Each number must be between 1 and 255.
+If \fIdashList\fR is \f(CW""\fR, the grid will be solid lines.
+.TP
+\fB\-hide \fIboolean\fR
+Indicates whether the grid should be drawn. If \fIboolean\fR
+is true, grid lines are not shown. The default is \f(CWyes\fR.
+.TP
+\fB\-linewidth \fIpixels\fR
+Sets the width of grid lines. The default width is \f(CW1\fR.
+.TP
+\fB\-mapx \fIxAxis\fR
+Specifies the X\-axis to display grid lines. \fIXAxis\fR
+must be the name of an axis or \f(CW""\fR for no grid lines.
+The default is \f(CW""\fR.
+.TP
+\fB\-mapy \fIyAxis\fR
+Specifies the Y\-axis to display grid lines. \fIYAxis\fR
+must be the name of an axis or \f(CW""\fR for no grid lines.
+The default is \f(CWy\fR.
+.TP
+\fB\-minor \fIboolean\fR
+Indicates whether the grid lines should be drawn for minor ticks.
+If \fIboolean\fR is true, the lines will appear at
+minor tick intervals. The default is \f(CW1\fR.
+.PP
+Grid configuration options may also be set by the
+\fBoption\fR command. The resource name and class are \f(CWgrid\fR and
+\f(CWGrid\fR respectively.
+.CS
+option add *Graph.grid.LineWidth 2
+option add *Graph.Grid.Color black
+.CE
+.RE
+.TP
+\fIpathName \fBgrid off\fR
+Turns off the display the grid lines.
+.TP
+\fIpathName \fBgrid on\fR
+Turns on the display the grid lines.
+.TP
+\fIpathName \fBgrid toggle\fR
+Toggles the display of the grid.
+.SS "LEGEND COMPONENT"
+The legend displays a list of the data elements. Each entry consists
+of the element's symbol and label. The legend can appear in any
+margin (the default location is in the right margin). It
+can also be positioned anywhere within the plotting area.
+.PP
+The following operations are valid for the legend.
+.TP
+\fIpathName \fBlegend activate \fIpattern\fR...
+Selects legend entries to be drawn using the active legend colors and relief.
+All entries whose element names match \fIpattern\fR are selected. To
+be selected, the element name must match only one \fIpattern\fR.
+.TP
+\fIpathName \fBlegend bind \fItagName\fR ?\fIsequence\fR? ?\fIcommand\fR?
+Associates \fIcommand\fR with \fItagName\fR such that whenever the
+event sequence given by \fIsequence\fR occurs for a legend entry with this
+tag, \fIcommand\fR will be invoked. Implicitly the element names
+in the entry are tags. The syntax is similar to the
+\fBbind\fR command except that it operates on legend entries, rather
+than widgets. See the \fBbind\fR manual entry for
+complete details on \fIsequence\fR and the substitutions performed on
+\fIcommand\fR before invoking it.
+.sp
+If all arguments are specified then a new binding is created, replacing
+any existing binding for the same \fIsequence\fR and \fItagName\fR.
+If the first character of \fIcommand\fR is \f(CW+\fR then \fIcommand\fR
+augments an existing binding rather than replacing it.
+If no \fIcommand\fR argument is provided then the command currently
+associated with \fItagName\fR and \fIsequence\fR (it's an error occurs
+if there's no such binding) is returned. If both \fIcommand\fR and
+\fIsequence\fR are missing then a list of all the event sequences for
+which bindings have been defined for \fItagName\fR.
+.TP
+\fIpathName \fBlegend cget \fIoption\fR
+Returns the current value of a legend configuration option.
+\fIOption\fR may be any option described below in the
+legend \fBconfigure\fR operation.
+.TP
+\fIpathName \fBlegend configure \fR?\fIoption value\fR?...
+Queries or modifies the configuration options for the legend. If
+\fIoption\fR isn't specified, a list describing the current
+legend options for \fIpathName\fR is returned. If \fIoption\fR is
+specified, but not \fIvalue\fR, then a list describing \fIoption\fR is
+returned. If one or more \fIoption\fR and \fIvalue\fR pairs are
+specified, then for each pair, the legend option \fIoption\fR is set
+to \fIvalue\fR. The following options are valid for the legend.
+.RS
+.TP
+\fB\-activebackground \fIcolor\fR
+Sets the background color for active legend entries. All legend
+entries marked active (see the legend \fBactivate\fR operation) are
+drawn using this background color.
+.TP
+\fB\-activeborderwidth \fIpixels\fR
+Sets the width of the 3-D border around the outside edge of the active legend
+entries. The default is \f(CW2\fR.
+.TP
+\fB\-activeforeground \fIcolor\fR
+Sets the foreground color for active legend entries. All legend
+entries marked as active (see the legend \fBactivate\fR operation) are
+drawn using this foreground color.
+.TP
+\fB\-activerelief \fIrelief\fR
+Specifies the 3-D effect desired for active legend entries.
+\fIRelief\fR denotes how the interior of the entry should appear
+relative to the legend; for example, \f(CWraised\fR means the entry
+should appear to protrude from the legend, relative to the surface of
+the legend. The default is \f(CWflat\fR.
+.TP
+\fB\-anchor \fIanchor\fR
+Tells how to position the legend relative to the positioning point for
+the legend. This is dependent on the value of the \fB\-position\fR
+option. The default is \f(CWcenter\fR.
+.RS
+.TP 1.25i
+\f(CWleft\fR or \f(CWright\fR
+The anchor describes how to position the legend vertically.
+.TP
+\f(CWtop\fR or \f(CWbottom\fR
+The anchor describes how to position the legend horizontally.
+.TP
+\f(CW@x,y\fR
+The anchor specifies how to position the legend relative to the
+positioning point. For example, if \fIanchor\fR is \f(CWcenter\fR then
+the legend is centered on the point; if \fIanchor\fR is \f(CWn\fR then
+the legend will be drawn such that the top center point of the
+rectangular region occupied by the legend will be at the positioning
+point.
+.TP
+\f(CWplotarea\fR
+The anchor specifies how to position the legend relative to the
+plotting area. For example, if \fIanchor\fR is \f(CWcenter\fR then the
+legend is centered in the plotting area; if \fIanchor\fR is \f(CWne\fR
+then the legend will be drawn such that occupies the upper right
+corner of the plotting area.
+.RE
+.TP
+\fB\-background \fIcolor\fR
+Sets the background color of the legend. If \fIcolor\fR is \f(CW""\fR,
+the legend background with be transparent.
+.TP
+\fB\-bindtags \fItagList\fR
+Specifies the binding tags for legend entries. \fITagList\fR is a list
+of binding tag names. The tags and their order will determine how
+events are handled for legend entries. Each tag in the list matching
+the current event sequence will have its Tcl command executed. The
+default value is \f(CWall\fR.
+.TP
+\fB\-borderwidth \fIpixels\fR
+Sets the width of the 3-D border around the outside edge of the legend (if
+such border is being drawn; the \fBrelief\fR option determines this).
+The default is \f(CW2\fR pixels.
+.TP
+\fB\-font \fIfontName\fR
+\fIFontName\fR specifies a font to use when drawing the labels of each
+element into the legend. The default is
+\f(CW*-Helvetica-Bold-R-Normal-*-12-120-*\fR.
+.TP
+\fB\-foreground \fIcolor\fR
+Sets the foreground color of the text drawn for the element's label.
+The default is \f(CWblack\fR.
+.TP
+\fB\-hide \fIboolean\fR
+Indicates whether the legend should be displayed. If \fIboolean\fR is
+true, the legend will not be draw. The default is \f(CWno\fR.
+.TP
+\fB\-ipadx \fIpad\fR
+Sets the amount of internal padding to be added to the width of each
+legend entry. \fIPad\fR can be a list of one or two screen distances. If
+\fIpad\fR has two elements, the left side of the legend entry is
+padded by the first distance and the right side by the second. If
+\fIpad\fR is just one distance, both the left and right sides are padded
+evenly. The default is \f(CW2\fR.
+.TP
+\fB\-ipady \fIpad\fR
+Sets an amount of internal padding to be added to the height of each
+legend entry. \fIPad\fR can be a list of one or two screen distances. If
+\fIpad\fR has two elements, the top of the entry is padded by the
+first distance and the bottom by the second. If \fIpad\fR is just
+one distance, both the top and bottom of the entry are padded evenly.
+The default is \f(CW2\fR.
+.TP
+\fB\-padx \fIpad\fR
+Sets the padding to the left and right exteriors of the legend.
+\fIPad\fR can be a list of one or two screen distances. If \fIpad\fR
+has two elements, the left side of the legend is padded by the first
+distance and the right side by the second. If \fIpad\fR has just one
+distance, both the left and right sides are padded evenly. The
+default is \f(CW4\fR.
+.TP
+\fB\-pady \fIpad\fR
+Sets the padding above and below the legend. \fIPad\fR can be a list
+of one or two screen distances. If \fIpad\fR has two elements, the area above
+the legend is padded by the first distance and the area below by the
+second. If \fIpad\fR is just one distance, both the top and
+bottom areas are padded evenly. The default is \f(CW0\fR.
+.TP
+\fB\-position \fIpos\fR
+Specifies where the legend is drawn. The
+\fB\-anchor\fR option also affects where the legend is positioned. If
+\fIpos\fR is \f(CWleft\fR, \f(CWleft\fR, \f(CWtop\fR, or \f(CWbottom\fR, the
+legend is drawn in the specified margin. If \fIpos\fR is
+\f(CWplotarea\fR, then the legend is drawn inside the plotting area at a
+particular anchor. If \fIpos\fR is in the form "\fI@x,y\fR", where
+\fIx\fR and \fIy\fR are the window coordinates, the legend is drawn in
+the plotting area at the specified coordinates. The default is
+\f(CWright\fR.
+.TP
+\fB\-raised \fIboolean\fR
+Indicates whether the legend is above or below the data elements. This
+matters only if the legend is in the plotting area. If \fIboolean\fR
+is true, the legend will be drawn on top of any elements that may
+overlap it. The default is \f(CWno\fR.
+.TP
+\fB\-relief \fIrelief\fR
+Specifies the 3-D effect for the border around the legend.
+\fIRelief\fR specifies how the interior of the legend should appear
+relative to the graph; for example, \f(CWraised\fR means the legend
+should appear to protrude from the graph, relative to the surface of
+the graph. The default is \f(CWsunken\fR.
+.PP
+Legend configuration options may also be set by the \fBoption\fR
+command. The resource name and class are \f(CWlegend\fR and
+\f(CWLegend\fR respectively.
+.CS
+option add *Graph.legend.Foreground blue
+option add *Graph.Legend.Relief raised
+.CE
+.RE
+.TP
+\fIpathName \fBlegend deactivate \fIpattern\fR...
+Selects legend entries to be drawn using the normal legend colors and
+relief. All entries whose element names match \fIpattern\fR are
+selected. To be selected, the element name must match only one
+\fIpattern\fR.
+.TP
+\fIpathName \fBlegend get \fIpos\fR
+Returns the name of the element whose entry is at the screen position
+\fIpos\fR in the legend. \fIPos\fR must be in the form "\fI@x,y\fR",
+where \fIx\fR and \fIy\fR are window coordinates. If the given
+coordinates do not lie over a legend entry, \f(CW""\fR is returned.
+.SS "PEN COMPONENTS"
+Pens define attributes (both symbol and line style) for elements.
+Pens mirror the configuration options of data elements that pertain to
+how symbols and lines are drawn. Data elements use pens to determine
+how they are drawn. A data element may use several pens at once. In
+this case, the pen used for a particular data point is determined from
+each element's weight vector (see the element's \fB\-weight\fR and
+\fB\-style\fR options).
+.PP
+One pen, called \f(CWactiveLine\fR, is automatically created.
+It's used as the default active pen for elements. So you can change
+the active attributes for all elements by simply reconfiguring this
+pen.
+.CS
+\&.g pen configure "activeLine" -color green
+.CE
+You can create and use several pens. To create a pen, invoke
+the pen component and its create operation.
+.CS
+\&.g pen create myPen
+.CE
+You map pens to a data element using either the element's
+\fB\-pen\fR or \fB\-activepen\fR options.
+.CS
+\&.g element create "line1" -xdata $x -ydata $tempData \\
+ -pen myPen
+.CE
+An element can use several pens at once. This is done by specifying
+the name of the pen in the element's style list (see the
+\fB\-styles\fR option).
+.CS
+\&.g element configure "line1" -styles { myPen 2.0 3.0 }
+.CE
+This says that any data point with a weight between 2.0 and 3.0
+is to be drawn using the pen \f(CWmyPen\fR. All other points
+are drawn with the element's default attributes.
+.PP
+The following operations are available for pen components.
+.PP
+.TP
+\fIpathName \fBpen \fBcget \fIpenName \fIoption\fR
+Returns the current value of the option given by \fIoption\fR for
+\fIpenName\fR. \fIOption\fR may be any option described below
+for the pen \fBconfigure\fR operation.
+.TP
+\fIpathName \fBpen \fBconfigure \fIpenName \fR?\fIpenName\fR... ?\fIoption value\fR?...
+Queries or modifies the configuration options of
+\fIpenName\fR. Several pens can be modified at once. If \fIoption\fR
+isn't specified, a list describing the current options for
+\fIpenName\fR is returned. If \fIoption\fR is specified, but not
+\fIvalue\fR, then a list describing \fIoption\fR is returned. If one
+or more \fIoption\fR and \fIvalue\fR pairs are specified, then for
+each pair, the pen option \fIoption\fR is set to \fIvalue\fR. The
+following options are valid for pens.
+.RS
+.TP
+\fB\-color \fIcolor\fR
+Sets the color of the traces connecting the data points.
+.TP
+\fB\-dashes \fIdashList\fR
+Sets the dash style of element line. \fIDashList\fR is a list of up to
+11 numbers that alternately represent the lengths of the dashes and
+gaps on the element line. Each number must be between 1 and 255. If
+\fIdashList\fR is \f(CW""\fR, the lines will be solid.
+.TP
+\fB\-fill \fIcolor\fR
+Sets the interior color of symbols. If \fIcolor\fR is \f(CW""\fR, then
+the interior of the symbol is transparent. If \fIcolor\fR is
+\f(CWdefcolor\fR, then the color will be the same as the \fB\-color\fR
+option. The default is \f(CWdefcolor\fR.
+.TP
+\fB\-linewidth \fIpixels\fR
+Sets the width of the connecting lines between data points. If
+\fIpixels\fR is \f(CW0\fR, no connecting lines will be drawn between
+symbols. The default is \f(CW0\fR.
+.TP
+\fB\-offdash \fIcolor\fR
+Sets the color of the stripes when traces are dashed (see the
+\fB\-dashes\fR option). If \fIcolor\fR is \f(CW""\fR, then the "off"
+pixels will represent gaps instead of stripes. If \fIcolor\fR is
+\f(CWdefcolor\fR, then the color will be the same as the \fB\-color\fR
+option. The default is \f(CWdefcolor\fR.
+.TP
+\fB\-outline \fIcolor\fR
+Sets the color or the outline around each symbol. If \fIcolor\fR is
+\f(CW""\fR, then no outline is drawn. If \fIcolor\fR is \f(CWdefcolor\fR,
+then the color will be the same as the \fB\-color\fR option. The
+default is \f(CWdefcolor\fR.
+.TP
+\fB\-outlinewidth \fIpixels\fR
+Sets the width of the outline bordering each symbol. If \fIpixels\fR
+is \f(CW0\fR, no outline will be drawn. The default is \f(CW1\fR.
+.TP
+\fB\-pixels \fIpixels\fR
+Sets the size of symbols. If \fIpixels\fR is \f(CW0\fR, no symbols will
+be drawn. The default is \f(CW0.125i\fR.
+.TP
+\fB\-symbol \fIsymbol\fR
+Specifies the symbol for data points. \fISymbol\fR can be either
+\f(CWsquare\fR, \f(CWcircle\fR, \f(CWdiamond\fR, \f(CWplus\fR, \f(CWcross\fR,
+\f(CWsplus\fR, \f(CWscross\fR, \f(CWtriangle\fR, \f(CW""\fR (where no symbol
+is drawn), or a bitmap. Bitmaps are specified as "\fIsource\fR
+?\fImask\fR?", where \fIsource\fR is the name of the bitmap, and
+\fImask\fR is the bitmap's optional mask. The default is
+\f(CWcircle\fR.
+.TP
+\fB\-type \fIelemType\fR
+Specifies the type of element the pen is to be used with.
+This option should only be employed when creating the pen. This
+is for those that wish to mix different types of elements (bars and
+lines) on the same graph. The default type is "line".
+.PP
+Pen configuration options may be also be set by the \fBoption\fR
+command. The resource class is \f(CWPen\fR. The resource names
+are the names of the pens.
+.CS
+option add *Graph.Pen.Color blue
+option add *Graph.activeLine.color green
+.CE
+.RE
+.TP
+\fIpathName \fBpen \fBcreate \fIpenName \fR?\fIoption value\fR?...
+Creates a new pen by the name \fIpenName\fR. No pen by the same
+name can already exist. \fIOption\fR and \fIvalue\fR are described
+in above in the pen \fBconfigure\fR operation.
+.TP
+\fIpathName \fBpen \fBdelete \fR?\fIpenName\fR?...
+Deletes the named pens. A pen is not really
+deleted until it is not longer in use, so it's safe to delete
+pens mapped to elements.
+.TP
+\fIpathName \fBpen names \fR?\fIpattern\fR?...
+Returns a list of pens matching zero or more patterns. If no
+\fIpattern\fR argument is give, the names of all pens are returned.
+.SS "POSTSCRIPT COMPONENT"
+The graph can generate encapsulated PostScript output. There
+are several configuration options you can specify to control how the
+plot will be generated. You can change the page dimensions and
+borders. The plot itself can be scaled, centered, or rotated to
+landscape. The PostScript output can be written directly to a file or
+returned through the interpreter.
+.PP
+The following postscript operations are available.
+.TP
+\fIpathName \fBpostscript cget \fIoption\fR
+Returns the current value of the postscript option given by
+\fIoption\fR. \fIOption\fR may be any option described
+below for the postscript \fBconfigure\fR operation.
+.TP
+\fIpathName \fBpostscript configure \fR?\fIoption value\fR?...
+Queries or modifies the configuration options for PostScript
+generation. If \fIoption\fR isn't specified, a list describing
+the current postscript options for \fIpathName\fR is returned. If
+\fIoption\fR is specified, but not \fIvalue\fR, then a list describing
+\fIoption\fR is returned. If one or more \fIoption\fR and \fIvalue\fR
+pairs are specified, then for each pair, the postscript option
+\fIoption\fR is set to \fIvalue\fR. The following postscript options
+are available.
+.RS
+.TP
+\fB\-center \fIboolean\fR
+Indicates whether the plot should be centered on the PostScript page. If
+\fIboolean\fR is false, the plot will be placed in the upper left
+corner of the page. The default is \f(CW1\fR.
+.TP
+\fB\-colormap \fIvarName\fR
+\fIVarName\fR must be the name of a global array variable that
+specifies a color mapping from the X color name to PostScript. Each
+element of \fIvarName\fR must consist of PostScript code to set a
+particular color value (e.g. ``\f(CW1.0 1.0 0.0 setrgbcolor\fR''). When
+generating color information in PostScript, the array variable \fIvarName\fR
+is checked if an element of the name as the color exists. If so, it uses
+its value as the PostScript
+command to set the color. If this option hasn't been specified, or if
+there isn't an entry in \fIvarName\fR for a given color, then it uses
+the red, green, and blue intensities from the X color.
+.TP
+\fB\-colormode \fImode\fR
+Specifies how to output color information. \fIMode\fR must be either
+\f(CWcolor\fR (for full color output), \f(CWgray\fR (convert all colors to
+their gray-scale equivalents) or \f(CWmono\fR (convert foreground colors
+to black and background colors to white). The default mode is
+\f(CWcolor\fR.
+.TP
+\fB\-fontmap \fIvarName\fR
+\fIVarName\fR must be the name of a global array variable that
+specifies a font mapping from the X font name to PostScript. Each
+element of \fIvarName\fR must consist of a Tcl list with one or two
+elements; the name and point size of a PostScript font.
+When outputting PostScript commands for a particular font, the array
+variable \fIvarName\fR is checked to see if an element by the
+specified font exists. If there is such an element, then the font
+information contained in that element is used in the PostScript
+output. (If the point size is omitted from the list, the point size
+of the X font is used). Otherwise the X font is examined in an
+attempt to guess what PostScript font to use. This works only for
+fonts whose foundry property is \fIAdobe\fR (such as Times, Helvetica,
+Courier, etc.). If all of this fails then the font defaults to
+\f(CWHelvetica-Bold\fR.
+.TP
+\fB\-decorations \fIboolean\fR
+Indicates whether PostScript commands to generate color backgrounds and 3-D
+borders will be output. If \fIboolean\fR is false, the background will be
+white and no 3-D borders will be generated. The
+default is \f(CW1\fR.
+.TP
+\fB\-height \fIpixels\fR
+Sets the height of the plot. This lets you print the graph with a
+height different from the one drawn on the screen. If
+\fIpixels\fR is 0, the height is the same as the widget's height.
+The default is \f(CW0\fR.
+.TP
+\fB\-landscape \fIboolean\fR
+If \fIboolean\fR is true, this specifies the printed area is to be
+rotated 90 degrees. In non-rotated output the X\-axis of the printed
+area runs along the short dimension of the page (``portrait''
+orientation); in rotated output the X\-axis runs along the long
+dimension of the page (``landscape'' orientation). Defaults to
+\f(CW0\fR.
+.TP
+\fB\-maxpect \fIboolean\fR
+Indicates to scale the plot so that it fills the PostScript page.
+The aspect ratio of the graph is still retained. The default is
+\f(CW0\fR.
+.TP
+\fB\-padx \fIpad\fR
+Sets the horizontal padding for the left and right page borders. The
+borders are exterior to the plot. \fIPad\fR can be a list of one or
+two screen distances. If \fIpad\fR has two elements, the left border is padded
+by the first distance and the right border by the second. If
+\fIpad\fR has just one distance, both the left and right borders are
+padded evenly. The default is \f(CW1i\fR.
+.TP
+\fB\-pady \fIpad\fR
+Sets the vertical padding for the top and bottom page borders. The
+borders are exterior to the plot. \fIPad\fR can be a list of one or
+two screen distances. If \fIpad\fR has two elements, the top border is padded
+by the first distance and the bottom border by the second. If
+\fIpad\fR has just one distance, both the top and bottom borders are
+padded evenly. The default is \f(CW1i\fR.
+.TP
+\fB\-paperheight \fIpixels\fR
+Sets the height of the postscript page. This can be used to select
+between different page sizes (letter, A4, etc). The default height is
+\f(CW11.0i\fR.
+.TP
+\fB\-paperwidth \fIpixels\fR
+Sets the width of the postscript page. This can be used to select
+between different page sizes (letter, A4, etc). The default width is
+\f(CW8.5i\fR.
+.TP
+\fB\-width \fIpixels\fR
+Sets the width of the plot. This lets you generate a plot
+of a width different from that of the widget. If \fIpixels\fR
+is 0, the width is the same as the widget's width. The default is
+\f(CW0\fR.
+.PP
+Postscript configuration options may be also be set by the
+\fBoption\fR command. The resource name and class are
+\f(CWpostscript\fR and \f(CWPostscript\fR respectively.
+.CS
+option add *Graph.postscript.Decorations false
+option add *Graph.Postscript.Landscape true
+.CE
+.RE
+.TP
+\fIpathName \fBpostscript output \fR?\fIfileName\fR? ?\fIoption value\fR?...
+Outputs a file of encapsulated PostScript. If a
+\fIfileName\fR argument isn't present, the command returns the
+PostScript. If any \fIoption-value\fR pairs are present, they set
+configuration options controlling how the PostScript is generated.
+\fIOption\fR and \fIvalue\fR can be anything accepted by the
+postscript \fBconfigure\fR operation above.
+.SS "MARKER COMPONENTS"
+Markers are simple drawing procedures used to annotate or highlight
+areas of the graph. Markers have various types: text strings,
+bitmaps, images, connected lines, windows, or polygons. They can be
+associated with a particular element, so that when the element is
+hidden or un-hidden, so is the marker. By default, markers are the
+last items drawn, so that data elements will appear in
+behind them. You can change this by configuring the \fB\-under\fR
+option.
+.PP
+Markers, in contrast to elements, don't affect the scaling of the
+coordinate axes. They can also have \fIelastic\fR coordinates
+(specified by \f(CW-Inf\fR and \f(CWInf\fR respectively) that translate
+into the minimum or maximum limit of the axis. For example, you can
+place a marker so it always remains in the lower left corner of the
+plotting area, by using the coordinates \f(CW-Inf\fR,\f(CW-Inf\fR.
+.PP
+The following operations are available for markers.
+.TP
+\fIpathName \fBmarker after \fImarkerId\fR ?\fIafterId\fR?
+Changes the order of the markers, drawing the first
+marker after the second. If no second \fIafterId\fR argument is
+specified, the marker is placed at the end of the display list. This
+command can be used to control how markers are displayed since markers
+are drawn in the order of this display list.
+.TP
+\fIpathName \fBmarker before \fImarkerId\fR ?\fIbeforeId\fR?
+Changes the order of the markers, drawing the first
+marker before the second. If no second \fIbeforeId\fR argument is
+specified, the marker is placed at the beginning of the display list.
+This command can be used to control how markers are displayed since
+markers are drawn in the order of this display list.
+.TP
+\fIpathName \fBmarker bind \fItagName\fR ?\fIsequence\fR? ?\fIcommand\fR?
+Associates \fIcommand\fR with \fItagName\fR such that whenever the
+event sequence given by \fIsequence\fR occurs for a marker with this
+tag, \fIcommand\fR will be invoked. The syntax is similar to the
+\fBbind\fR command except that it operates on graph markers, rather
+than widgets. See the \fBbind\fR manual entry for
+complete details on \fIsequence\fR and the substitutions performed on
+\fIcommand\fR before invoking it.
+.sp
+If all arguments are specified then a new binding is created, replacing
+any existing binding for the same \fIsequence\fR and \fItagName\fR.
+If the first character of \fIcommand\fR is \f(CW+\fR then \fIcommand\fR
+augments an existing binding rather than replacing it.
+If no \fIcommand\fR argument is provided then the command currently
+associated with \fItagName\fR and \fIsequence\fR (it's an error occurs
+if there's no such binding) is returned. If both \fIcommand\fR and
+\fIsequence\fR are missing then a list of all the event sequences for
+which bindings have been defined for \fItagName\fR.
+.TP
+\fIpathName \fBmarker cget \fIoption\fR
+Returns the current value of the marker configuration option given by
+\fIoption\fR. \fIOption\fR may be any option described
+below in the \fBconfigure\fR operation.
+.TP
+\fIpathName \fBmarker configure \fImarkerId\fR ?\fIoption value\fR?...
+Queries or modifies the configuration options for markers. If
+\fIoption\fR isn't specified, a list describing the current
+options for \fImarkerId\fR is returned. If \fIoption\fR is specified,
+but not \fIvalue\fR, then a list describing \fIoption\fR is returned.
+If one or more \fIoption\fR and \fIvalue\fR pairs are specified, then
+for each pair, the marker option \fIoption\fR is set to \fIvalue\fR.
+.sp
+The following options are valid for all markers.
+Each type of marker also has its own type-specific options.
+They are described in the sections below.
+.RS
+.TP
+\fB\-bindtags \fItagList\fR
+Specifies the binding tags for the marker. \fITagList\fR is a list
+of binding tag names. The tags and their order will determine how
+events for markers are handled. Each tag in the list matching the
+current event sequence will have its Tcl command executed. Implicitly
+the name of the marker is always the first tag in the list.
+The default value is \f(CWall\fR.
+.TP
+\fB\-coords \fIcoordList\fR
+Specifies the coordinates of the marker. \fICoordList\fR is
+a list of graph coordinates. The number of coordinates required
+is dependent on the type of marker. Text, image, and window markers
+need only two coordinates (an X\-Y coordinate). Bitmap markers
+can take either two or four coordinates (if four, they represent the
+corners of the bitmap). Line markers
+need at least four coordinates, polygons at least six.
+If \fIcoordList\fR is \f(CW""\fR, the marker will not be displayed.
+The default is \f(CW""\fR.
+.TP
+\fB\-element \fIelemName\fR
+Links the marker with the element \fIelemName\fR. The marker is
+drawn only if the element is also currently displayed (see the
+element's \fBshow\fR operation). If \fIelemName\fR is \f(CW""\fR, the
+marker is always drawn. The default is \f(CW""\fR.
+.TP
+\fB\-hide \fIboolean\fR
+Indicates whether the marker is drawn. If \fIboolean\fR is true,
+the marker is not drawn. The default is \f(CWno\fR.
+.TP
+\fB\-mapx \fIxAxis\fR
+Specifies the X\-axis to map the marker's X\-coordinates onto.
+\fIXAxis\fR must the name of an axis. The default is \f(CWx\fR.
+.TP
+\fB\-mapy \fIyAxis\fR
+Specifies the Y\-axis to map the marker's Y\-coordinates onto.
+\fIYAxis\fR must the name of an axis. The default is \f(CWy\fR.
+.TP
+\fB\-name \fImarkerId\fR
+Changes the identifier for the marker. The identifier \fImarkerId\fR
+can not already be used by another marker. If this option
+isn't specified, the marker's name is uniquely generated.
+.TP
+\fB\-under \fIboolean\fR
+Indicates whether the marker is drawn below/above data
+elements. If \fIboolean\fR is true, the marker is be drawn
+underneath the data element symbols and lines. Otherwise, the marker is
+drawn on top of the element. The default is \f(CW0\fR.
+.TP
+\fB\-xoffset \fIpixels\fR
+Specifies a screen distance to offset the marker horizontally.
+\fIPixels\fR is a valid screen distance, such as \f(CW2\fR or \f(CW1.2i\fR.
+The default is \f(CW0\fR.
+.TP
+\fB\-yoffset \fIpixels\fR
+Specifies a screen distance to offset the markers vertically.
+\fIPixels\fR is a valid screen distance, such as \f(CW2\fR or \f(CW1.2i\fR.
+The default is \f(CW0\fR.
+.PP
+Marker configuration options may also be set by the \fBoption\fR command.
+The resource class is either \f(CWBitmapMarker\fR, \f(CWImageMarker\fR,
+\f(CWLineMarker\fR, \f(CWPolygonMarker\fR, \f(CWTextMarker\fR, or \f(CWWindowMarker\fR,
+depending on the type of marker. The resource name is the name of the
+marker.
+.CS
+option add *Graph.TextMarker.Foreground white
+option add *Graph.BitmapMarker.Foreground white
+option add *Graph.m1.Background blue
+.CE
+.RE
+.TP
+\fIpathName \fBmarker create \fItype\fR ?\fIoption value\fR?...
+Creates a marker of the selected type. \fIType\fR may be either
+\f(CWtext\fR, \f(CWline\fR, \f(CWbitmap\fR, \f(CWimage\fR, \f(CWpolygon\fR, or
+\f(CWwindow\fR. This command returns the marker identifier,
+used as the \fImarkerId\fR argument in the other marker-related
+commands. If the \fB\-name\fR option is used, this overrides the
+normal marker identifier. If the name provided is already used for
+another marker, the new marker will replace the old.
+.TP
+\fIpathName \fBmarker delete\fR ?\fIname\fR?...
+Removes one of more markers. The graph will automatically be redrawn
+without the marker.\fR.
+.TP
+\fIpathName \fBmarker exists \fImarkerId\fR
+Returns \f(CW1\fR if the marker \fImarkerId\fR exists and \f(CW0\fR
+otherwise.
+.TP
+\fIpathName \fBmarker names\fR ?\fIpattern\fR?
+Returns the names of all the markers that currently exist. If
+\fIpattern\fR is supplied, only those markers whose names match it
+will be returned.
+.TP
+\fIpathName \fBmarker type \fImarkerId\fR
+Returns the type of the marker given by \fImarkerId\fR, such as
+\f(CWline\fR or \f(CWtext\fR. If \fImarkerId\fR is not a valid a marker
+identifier, \f(CW""\fR is returned.
+.SS "BITMAP MARKERS"
+A bitmap marker displays a bitmap. The size of the
+bitmap is controlled by the number of coordinates specified. If two
+coordinates, they specify the position of the top-left corner of the
+bitmap. The bitmap retains its normal width and height. If four
+coordinates, the first and second pairs of coordinates represent the
+corners of the bitmap. The bitmap will be stretched or reduced as
+necessary to fit into the bounding rectangle.
+.PP
+Bitmap markers are created with the marker's \fBcreate\fR operation in
+the form:
+.DS
+\fIpathName \fBmarker create bitmap \fR?\fIoption value\fR?...
+.DE
+There may be many \fIoption\fR-\fIvalue\fR pairs, each
+sets a configuration options for the marker. These
+same \fIoption\fR\-\fIvalue\fR pairs may be used with the marker's
+\fBconfigure\fR operation.
+.PP
+The following options are specific to bitmap markers:
+.TP
+\fB\-background \fIcolor\fR
+Same as the \fB\-fill\fR option.
+.TP
+\fB\-bitmap \fIbitmap\fR
+Specifies the bitmap to be displayed. If \fIbitmap\fR is \f(CW""\fR,
+the marker will not be displayed. The default is \f(CW""\fR.
+.TP
+\fB\-fill \fIcolor\fR
+Sets the background color of the bitmap. If \fIcolor\fR is the empty
+string, no background will be transparent. The default background color is
+\f(CW""\fR.
+.TP
+\fB\-foreground \fIcolor\fR
+Same as the \fB\-outline\fR option.
+.TP
+\fB\-mask \fImask\fR
+Specifies a mask for the bitmap to be displayed. This mask is a bitmap
+itself, denoting the pixels that are transparent. If \fImask\fR is
+\f(CW""\fR, all pixels of the bitmap will be drawn. The default is
+\f(CW""\fR.
+.TP
+\fB\-outline \fIcolor\fR
+Sets the foreground color of the bitmap. The default value is \f(CWblack\fR.
+.TP
+\fB\-rotate \fItheta\fR
+Sets the rotation of the bitmap. \fITheta\fR is a real number
+representing the angle of rotation in degrees. The marker is first
+rotated and then placed according to its anchor position. The default
+rotation is \f(CW0.0\fR.
+.SS "IMAGE MARKERS"
+A image marker displays an image. Image markers are
+created with the marker's \fBcreate\fR operation in the form:
+.DS
+\fIpathName \fBmarker create image \fR?\fIoption value\fR?...
+.DE
+There may be many \fIoption\fR-\fIvalue\fR
+pairs, each sets a configuration option
+for the marker. These same \fIoption\fR\-\fIvalue\fR pairs may be
+used with the marker's \fBconfigure\fR operation.
+.PP
+The following options are specific to image markers:
+.TP
+\fB\-anchor \fIanchor\fR
+\fIAnchor\fR tells how to position the image relative to the
+positioning point for the image. For example, if \fIanchor\fR
+is \f(CWcenter\fR then the image is centered on the point; if
+\fIanchor\fR is \f(CWn\fR then the image will be drawn such that
+the top center point of the rectangular region occupied by the
+image will be at the positioning point.
+This option defaults to \f(CWcenter\fR.
+.TP
+\fB\-image \fIimage\fR
+Specifies the image to be drawn.
+If \fIimage\fR is \f(CW""\fR, the marker will not be
+drawn. The default is \f(CW""\fR.
+.SS "LINE MARKERS"
+A line marker displays one or more connected line segments.
+Line markers are created with marker's \fBcreate\fR operation in the form:
+.DS
+\fIpathName \fBmarker create line \fR?\fIoption value\fR?...
+.DE
+There may be many \fIoption\fR-\fIvalue\fR
+pairs, each sets a configuration option
+for the marker. These same \fIoption\fR-\fIvalue\fR pairs may be
+used with the marker's \fBconfigure\fR operation.
+.PP
+The following options are specific to line markers:
+.TP
+\fB\-dashes \fIdashList\fR
+Sets the dash style of the line. \fIDashList\fR is a list of up to 11
+numbers that alternately represent the lengths of the dashes and gaps
+on the line. Each number must be between 1 and 255. If
+\fIdashList\fR is \f(CW""\fR, the marker line will be solid.
+.TP
+\fB\-fill \fIcolor\fR
+Sets the background color of the line. This color is used with
+striped lines (see the \fB\-fdashes\fR option). If \fIcolor\fR is
+the empty string, no background color is drawn (the line will be
+dashed, not striped). The default background color is \f(CW""\fR.
+.TP
+\fB\-linewidth \fIpixels\fR
+Sets the width of the lines.
+The default width is \f(CW0\fR.
+.TP
+\fB\-outline \fIcolor\fR
+Sets the foreground color of the line. The default value is \f(CWblack\fR.
+.TP
+\fB\-stipple \fIbitmap\fR
+Specifies a stipple pattern used to draw the line, rather than
+a solid line.
+\fIBitmap\fR specifies a bitmap to use as the stipple
+pattern. If \fIbitmap\fR is \f(CW""\fR, then the
+line is drawn in a solid fashion. The default is \f(CW""\fR.
+.SS "POLYGON MARKERS"
+A polygon marker displays a closed region described as two or more
+connected line segments. It is assumed the first and
+last points are connected. Polygon markers are created using the
+marker \fBcreate\fR operation in the form:
+.DS
+\fIpathName \fBmarker create polygon \fR?\fIoption value\fR?...
+.DE
+There may be many \fIoption\fR-\fIvalue\fR
+pairs, each sets a configuration option
+for the marker. These same \fIoption\fR\-\fIvalue\fR pairs may be
+used with the \fBmarker configure\fR command to change the marker's
+configuration.
+The following options are supported for polygon markers:
+.TP
+\fB\-dashes \fIdashList\fR
+Sets the dash style of the outline of the polygon. \fIDashList\fR is a
+list of up to 11 numbers that alternately represent the lengths of
+the dashes and gaps on the outline. Each number must be between 1 and
+255. If \fIdashList\fR is \f(CW""\fR, the outline will be a solid line.
+.TP
+\fB\-fill \fIcolor\fR
+Sets the fill color of the polygon. If \fIcolor\fR is \f(CW""\fR, then
+the interior of the polygon is transparent.
+The default is \f(CWwhite\fR.
+.TP
+\fB\-linewidth \fIpixels\fR
+Sets the width of the outline of the polygon. If \fIpixels\fR is zero,
+no outline is drawn. The default is \f(CW0\fR.
+.TP
+\fB\-outline \fIcolor\fR
+Sets the color of the outline of the polygon. If the polygon is
+stippled (see the \fB\-stipple\fR option), then this represents the
+foreground color of the stipple. The default is \f(CWblack\fR.
+.TP
+\fB\-stipple \fIbitmap\fR
+Specifies that the polygon should be drawn with a stippled pattern
+rather than a solid color. \fIBitmap\fR specifies a bitmap to use as
+the stipple pattern. If \fIbitmap\fR is \f(CW""\fR, then the polygon is
+filled with a solid color (if the \fB\-fill\fR option is set). The
+default is \f(CW""\fR.
+.SS "TEXT MARKERS"
+A text marker displays a string of characters on one or more lines of
+text. Embedded newlines cause line breaks. They may be used to
+annotate regions of the graph. Text markers are created with the
+\fBcreate\fR operation in the form:
+.DS
+\fIpathName \fBmarker create text \fR?\fIoption value\fR?...
+.DE
+There may be many \fIoption\fR-\fIvalue\fR pairs,
+each sets a configuration option for the text marker.
+These same \fIoption\fR\-\fIvalue\fR pairs may be used with the
+marker's \fBconfigure\fR operation.
+.PP
+The following options are specific to text markers:
+.TP
+\fB\-anchor \fIanchor\fR
+\fIAnchor\fR tells how to position the text relative to the
+positioning point for the text. For example, if \fIanchor\fR is
+\f(CWcenter\fR then the text is centered on the point; if
+\fIanchor\fR is \f(CWn\fR then the text will be drawn such that the
+top center point of the rectangular region occupied by the text will
+be at the positioning point. This default is \f(CWcenter\fR.
+.TP
+\fB\-background \fIcolor\fR
+Same as the \fB\-fill\fR option.
+.TP
+\fB\-font \fIfontName\fR
+Specifies the font of the text. The default is
+\f(CW*-Helvetica-Bold-R-Normal-*-120-*\fR.
+.TP
+\fB\-fill \fIcolor\fR
+Sets the background color of the text. If \fIcolor\fR is the empty
+string, no background will be transparent. The default background color is
+\f(CW""\fR.
+.TP
+\fB\-foreground \fIcolor\fR
+Same as the \fB\-outline\fR option.
+.TP
+\fB\-justify \fIjustify\fR
+Specifies how the text should be justified. This matters only when
+the marker contains more than one line of text. \fIJustify\fR must be
+\f(CWleft\fR, \f(CWright\fR, or \f(CWcenter\fR. The default is
+\f(CWcenter\fR.
+.TP
+\fB\-outline \fIcolor\fR
+Sets the color of the text. The default value is \f(CWblack\fR.
+.TP
+\fB\-padx \fIpad\fR
+Sets the padding to the left and right exteriors of the text.
+\fIPad\fR can be a list of one or two screen distances. If \fIpad\fR
+has two elements, the left side of the text is padded by the first
+distance and the right side by the second. If \fIpad\fR has just one
+distance, both the left and right sides are padded evenly. The
+default is \f(CW4\fR.
+.TP
+\fB\-pady \fIpad\fR
+Sets the padding above and below the text. \fIPad\fR can be a list of
+one or two screen distances. If \fIpad\fR has two elements, the area above the
+text is padded by the first distance and the area below by the second.
+If \fIpad\fR is just one distance, both the top and bottom areas
+are padded evenly. The default is \f(CW4\fR.
+.TP
+\fB\-rotate \fItheta\fR
+Specifies the number of degrees to rotate the text. \fITheta\fR is a
+real number representing the angle of rotation. The marker is first
+rotated along its center and is then drawn according to its anchor
+position. The default is \f(CW0.0\fR.
+.TP
+\fB\-text \fItext\fR
+Specifies the text of the marker. The exact way the text is
+displayed may be affected by other options such as \fB\-anchor\fR or
+\fB\-rotate\fR.
+.SS "WINDOW MARKERS"
+A window marker displays a widget at a given position.
+Window markers are created with the marker's \fBcreate\fR operation in
+the form:
+.DS
+\fIpathName \fBmarker create window \fR?\fIoption value\fR?...
+.DE
+There may be many \fIoption\fR-\fIvalue\fR
+pairs, each sets a configuration option
+for the marker. These same \fIoption\fR\-\fIvalue\fR pairs may be
+used with the marker's \fBconfigure\fR command.
+.PP
+The following options are specific to window markers:
+.TP
+\fB\-anchor \fIanchor\fR
+\fIAnchor\fR tells how to position the widget relative to the
+positioning point for the widget. For example, if \fIanchor\fR is
+\f(CWcenter\fR then the widget is centered on the point; if \fIanchor\fR
+is \f(CWn\fR then the widget will be displayed such that the top center
+point of the rectangular region occupied by the widget will be at the
+positioning point. This option defaults to \f(CWcenter\fR.
+.TP
+\fB\-height \fIpixels\fR
+Specifies the height to assign to the marker's window. If this option
+isn't specified, or if it is specified as \f(CW""\fR, then the window is
+given whatever height the widget requests internally.
+.TP
+\fB\-width \fIpixels\fR
+Specifies the width to assign to the marker's window. If this option
+isn't specified, or if it is specified as \f(CW""\fR, then the window is
+given whatever width the widget requests internally.
+.TP
+\fB\-window \fIpathName\fR
+Specifies the widget to be managed by the graph. \fIPathName\fR must
+be a child of the \fBgraph\fR widget.
+.SH "GRAPH COMPONENT BINDINGS"
+Specific graph components, such as elements, markers and legend
+entries, can have a command trigger when event occurs in them, much
+like canvas items in Tk's canvas widget. Not all event sequences are
+valid. The only binding events that may be specified are those
+related to the mouse and keyboard (such as \fBEnter\fR, \fBLeave\fR,
+\fBButtonPress\fR, \fBMotion\fR, and \fBKeyPress\fR).
+.PP
+Only one element or marker can be picked during an event. This means,
+that if the mouse is directly over both an element and a marker, only
+the uppermost component is selected. This isn't true for legend entries.
+Both a legend entry and an element (or marker) binding commands
+will be invoked if both items are picked.
+.PP
+It is possible for multiple bindings to match a particular event.
+This could occur, for example, if one binding is associated with the
+element name and another is associated with one of the element's tags
+(see the \fB\-bindtags\fR option). When this occurs, all of the
+matching bindings are invoked. A binding associated with the element
+name is invoked first, followed by one binding for each of the element's
+bindtags. If there are multiple matching bindings for a single tag,
+then only the most specific binding is invoked. A continue command
+in a binding script terminates that script, and a break command
+terminates that script and skips any remaining scripts for the event,
+just as for the bind command.
+.PP
+The \fB\-bindtags\fR option for these components controls addition
+tag names which can be matched. Implicitly elements and markers
+always have tags matching their names. Setting the value of
+the \fB\-bindtags\fR option doesn't change this.
+.SH "C LANGUAGE API"
+You can manipulate data elements from the C language. There
+may be situations where it is too expensive to translate the data
+values from ASCII strings. Or you might want to read data in a
+special file format.
+.PP
+Data can manipulated from the C language using BLT vectors.
+You specify the X-Y data coordinates of an element as vectors and
+manipulate the vector from C. The graph will be redrawn automatically
+after the vectors are updated.
+.PP
+From Tcl, create the vectors and configure the element to use them.
+.CS
+vector X Y
+\&.g element configure line1 -xdata X -ydata Y
+.CE
+To set data points from C, you pass the values as arrays of doubles
+using the \fBBlt_ResetVector\fR call. The vector is reset with the
+new data and at the next idle point (when Tk re-enters its event
+loop), the graph will be redrawn automatically.
+.CS
+#include <tcl.h>
+#include <blt.h>
+
+register int i;
+Blt_Vector *xVec, *yVec;
+double x[50], y[50];
+
+/* Get the BLT vectors "X" and "Y" (created above from Tcl) */
+if ((Blt_GetVector(interp, "X", &xVec) != TCL_OK) ||
+ (Blt_GetVector(interp, "Y", &yVec) != TCL_OK)) {
+ return TCL_ERROR;
+}
+
+for (i = 0; i < 50; i++) {
+ x[i] = i * 0.02;
+ y[i] = sin(x[i]);
+}
+
+/* Put the data into BLT vectors */
+if ((Blt_ResetVector(xVec, x, 50, 50, TCL_VOLATILE) != TCL_OK) ||
+ (Blt_ResetVector(yVec, y, 50, 50, TCL_VOLATILE) != TCL_OK)) {
+ return TCL_ERROR;
+}
+.CE
+See the \fBvector\fR manual page for more details.
+.SH SPEED TIPS
+There may be cases where the graph needs to be drawn and updated as
+quickly as possible. If drawing speed becomes a big
+problem, here are a few tips to speed up displays.
+.TP 2
+\(bu
+Try to minimize the number of data points. The more data points
+the looked at, the more work the graph must do.
+.TP 2
+\(bu
+If your data is generated as floating point values, the time required
+to convert the data values to and from ASCII strings can be
+significant, especially when there any many data points. You can
+avoid the redundant string-to-decimal conversions using the C API to
+BLT vectors.
+.TP 2
+\(bu
+Data elements without symbols are drawn faster than with symbols.
+Set the data element's \fB\-symbol\fR option to \f(CWnone\fR. If you need to
+draw symbols, try using the simple symbols such as \f(CWsplus\fR and
+\f(CWscross\fR.
+.TP 2
+\(bu
+Don't stipple or dash the element. Solid lines are much faster.
+.TP 2
+\(bu
+If you update data elements frequently, try turning off the
+widget's \fB\-bufferelements\fR option. When the graph is first
+displayed, it draws data elements into an internal pixmap. The pixmap
+acts as a cache, so that when the graph needs to be redrawn again, and
+the data elements or coordinate axes haven't changed, the pixmap is
+simply copied to the screen. This is especially useful when you are
+using markers to highlight points and regions on the graph. But if
+the graph is updated frequently, changing either the element data or
+coordinate axes, the buffering becomes redundant.
+.SH LIMITATIONS
+Auto-scale routines do not use requested min/max limits as boundaries
+when the axis is logarithmically scaled.
+.PP
+The PostScript output generated for polygons with more than 1500
+points may exceed the limits of some printers (See PostScript Language
+Reference Manual, page 568). The work-around is to break the polygon
+into separate pieces.
+.SH KEYWORDS
+graph, widget