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| author | William Joye <wjoye@cfa.harvard.edu> | 2016-06-16 19:48:21 (GMT) |
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| committer | William Joye <wjoye@cfa.harvard.edu> | 2016-06-16 19:48:21 (GMT) |
| commit | 0c854c2841345e631ccb1b14c1f2703ba6274f7f (patch) | |
| tree | 89b4f4f8a52d34d15118f2c777ecd1f8b5eb0daf /doc/graph.html | |
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diff --git a/doc/graph.html b/doc/graph.html new file mode 100644 index 0000000..412c817 --- /dev/null +++ b/doc/graph.html @@ -0,0 +1,1751 @@ +<HTML> +<BODY> +<PRE> +<!-- Manpage converted by man2html 3.0.1 --> + +</PRE> +<H2>SYNOPSIS</H2><PRE> + <B>graph</B> <I>pathName</I> ?<I>option</I> <I>value</I>?... + + +</PRE> +<H2>DESCRIPTION</H2><PRE> + The <B>graph</B> 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. + + +</PRE> +<H2>INTRODUCTION</H2><PRE> + The <B>graph</B> 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 <I>plotting</I> <I>area</I>. + 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. + + The <B>graph</B> widget is composed of several components: coordinate axes, + data elements, legend, grid, cross hairs, pens, postscript, and annota- + tion markers. + + axis The graph has four standard axes (x, x2, y, and y2), 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. + + crosshairs + 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. + + element 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 sym- + bol, line width, and color is configurable. + + grid Extends the major and minor ticks of the X-axis and/or Y-axis + across the plotting area. + + legend The legend displays the name and symbol of each data element. + The legend can be drawn in any margin or in the plotting + area. + + marker 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 wid- + gets. + + <B>graph</B> <I>pathName</I> ?<I>option</I> <I>value</I>?... The <B>graph</B> command creates a new win- + dow <I>pathName</I> and makes it into a <B>graph</B> widget. At the time this com- + mand is invoked, there must not exist a window named <I>pathName</I>, but + <I>pathName</I>'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 <B>configure</B> operation below + for the exact details about what <I>option</I> and <I>value</I> pairs are valid. + + If successful, <B>graph</B> returns the path name of the widget. It also cre- + ates 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: <I>pathName</I> <I>operation</I> ?<I>arg</I>?... Both <I>operation</I> and its arguments + determine the exact behavior of the command. The operations available + for the graph are described in the <B>GRAPH</B> <B>OPERATIONS</B> section. + + The command can also be used to access components of the graph. <I>path-</I> + <I>Name</I> <I>component</I> <I>operation</I> ?<I>arg</I>?... The operation, now located after the + name of the component, is the function to be performed on that compo- + nent. Each component has its own set of operations that manipulate that + component. They will be described below in their own sections. + + +</PRE> +<H2>EXAMPLE</H2><PRE> + The <B>graph</B> command creates a new graph. # Create a new graph. Plotting + area is black. graph .g -plotbackground black A new Tcl command .g 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 <B>configure</B> operation. # Change the title. + .g configure -title "My Plot" 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 <B>element</B> component. + # 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 } The element's X-Y coordinates are specified using lists of + numbers. Alternately, BLT vectors could be used to hold the X-Y coor- + dinates. # 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 The advantage of + using vectors is that when you modify one, the graph is automatically + redrawn to reflect the new values. # Change the y coordinate of the + first point. set <B>yVector(0)</B> 25.18 An element named e1 is now created + in .b. 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 <B>show</B> + operation. # 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] 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 + example, you change the scale of the Y-axis from linear to log using + the <B>axis</B> component. # Y-axis is log scale. .g axis configure y + -logscale yes One important way axes are used is to zoom in on a par- + ticular data region. Zooming is done by simply specifying new axis + limits using the <B>-min</B> and <B>-max</B> configuration options. .g axis config- + ure x -min 1.0 -max 1.5 .g axis configure y -min 12.0 -max 55.15 To + zoom interactively, you link the <B>axis</B> <B>configure</B> operations with some + user interaction (such as pressing the mouse button), using the <B>bind</B> + command. To convert between screen and graph coordinates, use the + <B>invtransform</B> operation. # 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] } By default, + the limits of the axis are determined from data values. To reset back + to the default limits, set the <B>-min</B> and <B>-max</B> options to the empty + value. # Reset the axes to autoscale again. .g axis configure x -min + {} -max {} .g axis configure y -min {} -max {} By default, the legend + is drawn in the right margin. You can change this or any legend con- + figuration options using the <B>legend</B> component. # Configure the legend + font, color, and relief .g legend configure -position left -relief + raised \ -font fixed -fg blue To prevent the legend from being + displayed, turn on the <B>-hide</B> option. # Don't display the legend. .g + legend configure -hide yes The <B>graph</B> widget has simple drawing proce- + dures called markers. They can be used to highlight or annotate data + in the graph. The types of markers available are bitmaps, images, poly- + gons, 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 <B>marker</B> component. # 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 This creates a text marker named + first_marker. It will display the text "start" near the coordinates of + the first data point. The <B>-anchor</B>, <B>-xoffset</B>, and <B>-yoffset</B> 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 <B>-under</B> + option. # Draw the label before elements are drawn. .g marker config- + ure first_marker -under yes You can add cross hairs or grid lines using + the <B>crosshairs</B> and <B>grid</B> components. # Display both cross hairs and + grid lines. .g crosshairs configure -hide no -color red .g grid con- + figure -hide no -dashes { 2 2 } # Set up a binding to reposition the + crosshairs. bind .g <Motion> { + .g crosshairs configure -position @%x,%y } The crosshairs are repo- + sitioned as the mouse pointer is moved in the graph. The pointer X-Y + coordinates define the center of the crosshairs. + + Finally, to get hardcopy of the graph, use the <B>postscript</B> component. # + Print the graph into file "file.ps" .g postscript output file.ps -max- + pect yes -decorations no This generates a file file.ps containing the + encapsulated PostScript of the graph. The option <B>-maxpect</B> says to + scale the plot to the size of the page. Turning off the <B>-decorations</B> + option denotes that no borders or color backgrounds should be drawn + <I>option</I>. <I>Option</I> may be any option described below for the <B>con-</B> + <B>figure</B> operation. + + <I>pathName</I> <B>configure</B> ?<I>option</I> <I>value</I>?... + Queries or modifies the configuration options of the graph. If + <I>option</I> isn't specified, a list describing the current options + for <I>pathName</I> is returned. If <I>option</I> is specified, but not + <I>value</I>, then a list describing <I>option</I> is returned. If one or + more <I>option</I> and <I>value</I> pairs are specified, then for each pair, + the option <I>option</I> is set to <I>value</I>. The following options are + valid. + + <B>-aspect</B> <I>width/height</I> + Force a fixed aspect ratio of <I>width/height</I>, a floating + point number. + + <B>-background</B> <I>color</I> + Sets the background color. This includes the margins and + legend, but not the plotting area. + + <B>-borderwidth</B> <I>pixels</I> + Sets the width of the 3-D border around the outside edge + of the widget. The <B>-relief</B> option determines if the bor- + der is to be drawn. The default is 2. + + <B>-bottommargin</B> <I>pixels</I> + If non-zero, overrides the computed size of the margin + extending below the X-coordinate axis. If <I>pixels</I> is 0, + the automatically computed size is used. The default is + 0. + + <B>-bufferelements</B> <I>boolean</I> + Indicates whether an internal pixmap to buffer the dis- + play of data elements should be used. If <I>boolean</I> 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 <B>SPEED</B> + <B>TIPS</B> section. The default is 1. + + <B>-cursor</B> <I>cursor</I> + Specifies the widget's cursor. The default cursor is + crosshair. + + <B>-font</B> <I>fontName</I> + Specifies the font of the graph title. The default is + *-Helvetica-Bold-R-Normal-*-18-180-*. + + <B>-halo</B> <I>pixels</I> + Specifies a maximum distance to consider when searching + for the closest data point (see the element's <B>closest</B> + operation below). Data points further than <I>pixels</I> away + text. <I>Justify</I> must be left, right, or center. The + default is center. + + <B>-leftmargin</B> <I>pixels</I> + If non-zero, overrides the computed size of the margin + extending from the left edge of the window to the Y-coor- + dinate axis. If <I>pixels</I> is 0, the automatically computed + size is used. The default is 0. + + <B>-plotbackground</B> <I>color</I> + Specifies the background color of the plotting area. The + default is white. + + <B>-plotborderwidth</B> <I>pixels</I> + Sets the width of the 3-D border around the plotting + area. The <B>-plotrelief</B> option determines if a border is + drawn. The default is 2. + + <B>-plotpadx</B> <I>pad</I> + Sets the amount of padding to be added to the left and + right sides of the plotting area. <I>Pad</I> can be a list of + one or two screen distances. If <I>pad</I> 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 <I>pad</I> + is just one distance, both the left and right sides are + padded evenly. The default is 8. + + <B>-plotpady</B> <I>pad</I> + Sets the amount of padding to be added to the top and + bottom of the plotting area. <I>Pad</I> can be a list of one or + two screen distances. If <I>pad</I> has two elements, the top + of the plotting area is padded by the first distance and + the bottom by the second. If <I>pad</I> is just one distance, + both the top and bottom are padded evenly. The default + is 8. + + <B>-plotrelief</B> <I>relief</I> + Specifies the 3-D effect for the plotting area. <I>Relief</I> + specifies how the interior of the plotting area should + appear relative to rest of the graph; for example, raised + means the plot should appear to protrude from the graph, + relative to the surface of the graph. The default is + sunken. + + <B>-relief</B> <I>relief</I> + Specifies the 3-D effect for the graph widget. <I>Relief</I> + specifies how the graph should appear relative to widget + it is packed into; for example, raised means the graph + should appear to protrude. The default is flat. + + <B>-rightmargin</B> <I>pixels</I> + If non-zero, overrides the computed size of the margin + + <B>-tile</B> <I>image</I> + Specifies a tiled background for the widget. If <I>image</I> + isn't "", the background is tiled using <I>image</I>. Other- + wise, the normal background color is drawn (see the + <B>-background</B> option). <I>Image</I> must be an image created + using the Tk <B>image</B> command. The default is "". + + <B>-title</B> <I>text</I> + Sets the title to <I>text</I>. If <I>text</I> is "", no title will be + displayed. + + <B>-topmargin</B> <I>pixels</I> + If non-zero, overrides the computed size of the margin + above the x2 axis. If <I>pixels</I> is 0, the automatically + computed size is used. The default is 0. + + <B>-width</B> <I>pixels</I> + Specifies the requested width of the widget. The default + is 5i. + + <I>pathName</I> <B>crosshairs</B> <I>operation</I> ?<I>arg</I>? + See the <B>CROSSHAIRS</B> <B>COMPONENT</B> section. + + <I>pathName</I> <B>element</B> <I>operation</I> ?<I>arg</I>?... + See the <B>ELEMENT</B> <B>COMPONENTS</B> section. + + <I>pathName</I> <B>extents</B> <I>item</I> + Returns the size of a particular item in the graph. <I>Item</I> must + be either leftmargin, rightmargin, topmargin, bottommargin, + plotwidth, or plotheight. + + <I>pathName</I> <B>grid</B> <I>operation</I> ?<I>arg</I>?... + See the <B>GRID</B> <B>COMPONENT</B> section. + + <I>pathName</I> <B>invtransform</B> <I>winX</I> <I>winY</I> + 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 coordi- + nates. + + <I>pathName</I> <B>inside</B> <I>x</I> <I>y</I> + Returns 1 is the designated screen coordinate (<I>x</I> and <I>y</I>) is + inside the plotting area and 0 otherwise. + + <I>pathName</I> <B>legend</B> <I>operation</I> ?<I>arg</I>?... + See the <B>LEGEND</B> <B>COMPONENT</B> section. + + <I>pathName</I> <B>line</B> <B>operation</B> <B>arg</B>... + The operation is the same as <B>element</B>. + + <I>pathName</I> <B>marker</B> <I>operation</I> ?<I>arg</I>?... + photo Saves a Tk photo image. <I>OutputName</I> represents + the name of a Tk photo image that must already + have been created. + + wmf Saves an Aldus Placeable Metafile. <I>OutputName</I> + represents the filename where the metafile is + written. If <I>outputName</I> is CLIPBOARD, then out- + put is written directly to the Windows clip- + board. This format is available only under + Microsoft Windows. + + emf Saves an Enhanced Metafile. <I>OutputName</I> repre- + sents the filename where the metafile is writ- + ten. If <I>outputName</I> is CLIPBOARD, then output + is written directly to the Windows clipboard. + This format is available only under Microsoft + Windows. + + <B>-height</B> <I>size</I> + Specifies the height of the graph. <I>Size</I> is a screen + distance. The graph will be redrawn using this dimen- + sion, rather than its current window height. + + <B>-width</B> <I>size</I> + Specifies the width of the graph. <I>Size</I> is a screen + distance. The graph will be redrawn using this dimen- + sion, rather than its current window width. + + <I>pathName</I> <B>transform</B> <I>x</I> <I>y</I> + 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. + + <I>pathName</I> <B>xaxis</B> <I>operation</I> ?<I>arg</I>?... + + <I>pathName</I> <B>x2axis</B> <I>operation</I> ?<I>arg</I>?... + + <I>pathName</I> <B>yaxis</B> <I>operation</I> ?<I>arg</I>?... + + <I>pathName</I> <B>y2axis</B> <I>operation</I> ?<I>arg</I>?... + See the <B>AXIS</B> <B>COMPONENTS</B> section. + + +</PRE> +<H2>GRAPH COMPONENTS</H2><PRE> + A graph is composed of several components: coordinate axes, data ele- + ments, 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. + + <B>AXIS</B> <B>COMPONENTS</B> + Four coordinate axes are automatically created: two X-coordinate axes + You can have several axes. To create an axis, invoke the axis component + and its create operation. # Create a new axis called "tempAxis" .g + axis create tempAxis You map data elements to an axis using the ele- + ment's -mapy and -mapx configuration options. They specify the coordi- + nate axes an element is mapped onto. # Now map the tempAxis data to + this axis. .g element create "e1" -xdata $x -ydata $y -mapy tempAxis + Any number of axes can be displayed simultaneously. They are drawn in + the margins surrounding the plotting area. The default axes x and y + are drawn in the bottom and left margins. The axes x2 and y2 are drawn + in top and right margins. By default, only x and y are shown. Note + that the axes can have different scales. + + To display a different axis or more than one axis, you invoke one of + the following components: <B>xaxis</B>, <B>yaxis</B>, <B>x2axis</B>, and <B>y2axis</B>. Each com- + ponent has a <B>use</B> operation that designates the axis (or axes) to be + drawn in that corresponding margin: <B>xaxis</B> in the bottom, <B>yaxis</B> in the + left, <B>x2axis</B> in the top, and <B>y2axis</B> in the right. # Display the axis + tempAxis in the left margin. .g yaxis use tempAxis The <B>use</B> operation + takes a list of axis names as its last argument. This is the list of + axes to be drawn in this margin. + + 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. + + + <I>pathName</I> <B>axis</B> <B>bind</B> <I>tagName</I> ?<I>sequence</I>? ?<I>command</I>? + Associates <I>command</I> with <I>tagName</I> such that whenever the event + sequence given by <I>sequence</I> occurs for an axis with this tag, + <I>command</I> will be invoked. The syntax is similar to the <B>bind</B> com- + mand except that it operates on graph axes, rather than widgets. + See the <B>bind</B> manual entry for complete details on <I>sequence</I> and + the substitutions performed on <I>command</I> before invoking it. + + If all arguments are specified then a new binding is created, + replacing any existing binding for the same <I>sequence</I> and <I>tag-</I> + <I>Name</I>. If the first character of <I>command</I> is + then <I>command</I> aug- + ments an existing binding rather than replacing it. If no <I>com-</I> + <I>mand</I> argument is provided then the command currently associated + with <I>tagName</I> and <I>sequence</I> (it's an error occurs if there's no + such binding) is returned. If both <I>command</I> and <I>sequence</I> are + missing then a list of all the event sequences for which bind- + ings have been defined for <I>tagName</I>. + + <I>pathName</I> <B>axis</B> <B>cget</B> <I>axisName</I> <I>option</I> + Returns the current value of the option given by <I>option</I> for + <I>axisName</I>. <I>Option</I> may be any option described below for the axis + <B>configure</B> operation. + 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 all. + + <B>-color</B> <I>color</I> + Sets the color of the axis and tick labels. The default + is black. + + <B>-command</B> <I>prefix</I> + Specifies a Tcl command to be invoked when formatting the + axis tick labels. <I>Prefix</I> 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 "" is returned, no label will appear next to + the tick. You can get the standard tick labels again by + setting <I>prefix</I> to "". The default is "". + + 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. + + <B>-descending</B> <I>boolean</I> + Indicates whether the values along the axis are monotoni- + cally increasing or decreasing. If <I>boolean</I> is true, the + axis values will be decreasing. The default is 0. + + <B>-hide</B> <I>boolean</I> + Indicates if the axis is displayed. If <I>boolean</I> is false + the axis will be displayed. Any element mapped to the + axis is displayed regardless. The default value is 0. + + <B>-justify</B> <I>justify</I> + Specifies how the axis title should be justified. This + matters only when the axis title contains more than one + line of text. <I>Justify</I> must be left, right, or center. + The default is center. + + <B>-limits</B> <I>formatStr</I> + 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. <I>FormatStr</I> is a list of one or two format descrip- + tions. 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 "" is given as + either description, then the that limit will not be dis- + loosely, at the outer tick intervals. If the axis limit + is set with the -min or -max option, the axes are dis- + played tightly. If <I>boolean</I> is true, the axis range is + "loose". The default is 0. + + <B>-majorticks</B> <I>majorList</I> + Specifies where to display major axis ticks. You can use + this option to display ticks at non-uniform intervals. + <I>MajorList</I> is a list of axis coordinates designating the + location of major ticks. No minor ticks are drawn. If + <I>majorList</I> is "", major ticks will be automatically com- + puted. The default is "". + + <B>-max</B> <I>value</I> + Sets the maximum limit of <I>axisName</I>. Any data point + greater than <I>value</I> is not displayed. If <I>value</I> is "", the + maximum limit is calculated using the largest data value. + The default is "". + + <B>-min</B> <I>value</I> + Sets the minimum limit of <I>axisName</I>. Any data point less + than <I>value</I> is not displayed. If <I>value</I> is "", the minimum + limit is calculated using the smallest data value. The + default is "". + + <B>-minorticks</B> <I>minorList</I> + Specifies where to display minor axis ticks. You can use + this option to display minor ticks at non-uniform inter- + vals. <I>MinorList</I> 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 <B>-majortick</B> option is also + set. If <I>minorList</I> is "", minor ticks will be automati- + cally computed. The default is "". + + <B>-rotate</B> <I>theta</I> + Specifies the how many degrees to rotate the axis tick + labels. <I>Theta</I> is a real value representing the number of + degrees to rotate the tick labels. The default is 0.0 + degrees. + + <B>-scrollcommand</B> <I>command</I> + Specify the prefix for a command used to communicate with + scrollbars for this axis, such as <I>.sbar</I> <I>set</I>. + + <B>-scrollmax</B> <I>value</I> + Sets the maximum limit of the axis scroll region. If + <I>value</I> is "", the maximum limit is calculated using the + largest data value. The default is "". + + <B>-scrollmin</B> <I>value</I> + Sets the minimum limit of axis scroll region. If <I>value</I> + is "", the minimum limit is calculated using the smallest + Indicates how many minor axis ticks are to be drawn. For + example, if <I>number</I> is two, only one minor tick is drawn. + If <I>number</I> is one, no minor ticks are displayed. The + default is 2. + + <B>-tickfont</B> <I>fontName</I> + Specifies the font for axis tick labels. The default is + *-Courier-Bold-R-Normal-*-100-*. + + <B>-ticklength</B> <I>pixels</I> + Sets the length of major and minor ticks (minor ticks are + half the length of major ticks). If <I>pixels</I> is less than + zero, the axis will be inverted with ticks drawn pointing + towards the plot. The default is 0.1i. + + <B>-title</B> <I>text</I> + Sets the title of the axis. If <I>text</I> is "", no axis title + will be displayed. + + <B>-titlealternate</B> <I>boolean</I> + 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 0. + + <B>-titlecolor</B> <I>color</I> + Sets the color of the axis title. The default is black. + + <B>-titlefont</B> <I>fontName</I> + Specifies the font for axis title. The default is *-Hel- + vetica-Bold-R-Normal-*-14-140-*. + + Axis configuration options may be also be set by the <B>option</B> com- + mand. The resource class is Axis. The resource names are the + names of the axes (such as x or x2). option add + *Graph.Axis.Color blue option add *Graph.x.LogScale true + option add *Graph.x2.LogScale false + + <I>pathName</I> <B>axis</B> <B>create</B> <I>axisName</I> ?<I>option</I> <I>value</I>?... + Creates a new axis by the name <I>axisName</I>. No axis by the same + name can already exist. <I>Option</I> and <I>value</I> are described in above + in the axis <B>configure</B> operation. + + <I>pathName</I> <B>axis</B> <B>delete</B> ?<I>axisName</I>?... + 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 ele- + ments. + + <I>pathName</I> <B>axis</B> <B>invtransform</B> <I>axisName</I> <I>value</I> + Performs the inverse transformation, changing the screen coordi- + nate <I>value</I> to a graph coordinate, mapping the value mapped to + + <I>pathName</I> <B>axis</B> <B>view</B> <I>axisName</I> + Change the viewable area of this axis. Use as an argument to a + scrollbar's "<I>-command</I>". + + The default axes are x, y, x2, and y2. But you can display more than + four axes simultaneously. You can also swap in a different axis with + <B>use</B> operation of the special axis components: <B>xaxis</B>, <B>x2axis</B>, <B>yaxis</B>, and + <B>y2axis</B>. .g create axis temp .g create axis time ... .g xaxis use temp + .g yaxis use time Only the axes specified for use are displayed on the + screen. + + The <B>xaxis</B>, <B>x2axis</B>, <B>yaxis</B>, and <B>y2axis</B> components operate on an axis + location rather than a specific axis like the more general <B>axis</B> compo- + nent does. They implicitly control the axis that is currently using to + that location. By default, <B>xaxis</B> uses the x axis, <B>yaxis</B> uses y, <B>x2axis</B> + uses x2, and <B>y2axis</B> uses y2. When more than one axis is displayed in a + margin, it represents the first axis displayed. + + The following operations are available for axes. They mirror exactly + the operations of the <B>axis</B> component. The <I>axis</I> argument must be <B>xaxis</B>, + <B>x2axis</B>, <B>yaxis</B>, or <B>y2axis</B>. This feature is deprecated since more than + one axis can now be used a margin. You should only use the <B>xaxis</B>, + <B>x2axis</B>, <B>yaxis</B>, and <B>y2axis</B> components with the <B>use</B> operation. For all + other operations, use the general <B>axis</B> component instead. + + <I>pathName</I> <I>axis</I> <B>cget</B> <I>option</I> + + <I>pathName</I> <I>axis</I> <B>configure</B> ?<I>option</I> <I>value</I>?... + + <I>pathName</I> <I>axis</I> <B>invtransform</B> <I>value</I> + + <I>pathName</I> <I>axis</I> <B>limits</B> + + <I>pathName</I> <I>axis</I> <B>transform</B> <I>value</I> + + <I>pathName</I> <I>axis</I> <B>use</B> ?<I>axisName</I>? + Designates the axis <I>axisName</I> is to be displayed at this loca- + tion. <I>AxisName</I> can not be already in use at another location. + This command returns the name of the axis currently using this + location. + + <B>CROSSHAIRS</B> <B>COMPONENT</B> + 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 with- + out redrawing the entire graph. + + The following operations are available for cross hairs: + + <B>-color</B> <I>color</I> + Sets the color of the cross hairs. The default is black. + + <B>-dashes</B> <I>dashList</I> + Sets the dash style of the cross hairs. <I>DashList</I> 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 <I>dashList</I> is + "", the cross hairs will be solid lines. + + <B>-hide</B> <I>boolean</I> + Indicates whether cross hairs are drawn. If <I>boolean</I> is + true, cross hairs are not drawn. The default is yes. + + <B>-linewidth</B> <I>pixels</I> + Set the width of the cross hair lines. The default is 1. + + <B>-position</B> <I>pos</I> + Specifies the screen position where the cross hairs + intersect. <I>Pos</I> must be in the form "<I>@x,y</I>", where <I>x</I> and <I>y</I> + are the window coordinates of the intersection. + + Cross hairs configuration options may be also be set by the + <B>option</B> command. The resource name and class are crosshairs and + Crosshairs respectively. option add *Graph.Crosshairs.LineWidth + 2 option add *Graph.Crosshairs.Color red + + <I>pathName</I> <B>crosshairs</B> <B>off</B> + Turns off the cross hairs. + + <I>pathName</I> <B>crosshairs</B> <B>on</B> + Turns on the display of the cross hairs. + + <I>pathName</I> <B>crosshairs</B> <B>toggle</B> + Toggles the current state of the cross hairs, alternately map- + ping and unmapping the cross hairs. + + <B>ELEMENT</B> <B>COMPONENTS</B> + A data element represents a set of data. It contains x and y vectors + containing the coordinates of the data points. Elements can be dis- + played 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. + + 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. + + The following operations are available for elements. + + <I>pathName</I> <B>element</B> <B>activate</B> <I>elemName</I> ?<I>index</I>?... + Specifies the data points of element <I>elemName</I> to be drawn using + replacing any existing binding for the same <I>sequence</I> and <I>tag-</I> + <I>Name</I>. If the first character of <I>command</I> is + then <I>command</I> aug- + ments an existing binding rather than replacing it. If no <I>com-</I> + <I>mand</I> argument is provided then the command currently associated + with <I>tagName</I> and <I>sequence</I> (it's an error occurs if there's no + such binding) is returned. If both <I>command</I> and <I>sequence</I> are + missing then a list of all the event sequences for which bind- + ings have been defined for <I>tagName</I>. + + <I>pathName</I> <B>element</B> <B>cget</B> <I>elemName</I> <I>option</I> + Returns the current value of the element configuration option + given by <I>option</I>. <I>Option</I> may be any of the options described + below for the element <B>configure</B> operation. + + <I>pathName</I> <B>element</B> <B>closest</B> <I>x</I> <I>y</I> ?<I>option</I> <I>value</I>?... ?<I>elemName</I>?... + Searches for the data point closest to the window coordinates <I>x</I> + and <I>y</I>. By default, all elements are searched. Hidden elements + (see the <B>-hide</B> option is false) are ignored. You can limit the + search by specifying only the elements you want to be consid- + ered. <I>ElemName</I> 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 "", if no data point + within the threshold distance can be found. The following + <I>option</I>-<I>value</I> pairs are available. + + <B>-along</B> <I>direction</I> + Search for the closest element using the following crite- + ria: + + x Find closest element vertically from the given X- + coordinate. + + y Find the closest element horizontally from the + given Y-coordinate. + + both Find the closest element for the given point + (using both the X and Y coordinates). + + <B>-halo</B> <I>pixels</I> + Specifies a threshold distance where selected data points + are ignored. <I>Pixels</I> is a valid screen distance, such as + 2 or 1.2i. If this option isn't specified, then it + defaults to the value of the graph's <B>-halo</B> option. + + <B>-interpolate</B> <I>string</I> + Indicates whether to consider projections that lie along + the line segments connecting data points when searching + for the closest point. The default value is 0. The val- + ues for <I>string</I> are described below. + + no Search only for the closest data point. + + <B>-activepen</B> <I>penName</I> + Specifies pen to use to draw active element. If <I>penName</I> + is "", no active elements will be drawn. The default is + activeLine. + + <B>-areabackground</B> <I>color</I> + Specifies the background color of the area under the + curve. The background area color is drawn only for bit- + maps (see the <B>-areapattern</B> option). If <I>color</I> is "", the + background is transparent. The default is black. + + <B>-areaforeground</B> <I>color</I> + Specifies the foreground color of the area under the + curve. The default is black. + + <B>-areapattern</B> <I>pattern</I> + Specifies how to fill the area under the curve. <I>Pattern</I> + may be the name of a Tk bitmap, solid, or "". If + "solid", then the area under the curve is drawn with the + color designated by the <B>-areaforeground</B> option. If a + bitmap, then the bitmap is stippled across the area. + Here the bitmap colors are controlled by the <B>-areafore-</B> + <B>ground</B> and <B>-areabackground</B> options. If <I>pattern</I> is "", no + filled area is drawn. The default is "". + + <B>-areatile</B> <I>image</I> + Specifies the name of a Tk image to be used to tile the + area under the curve. This option supersedes the <B>-areap-</B> + <B>attern</B> option. <I>Image</I> must be a photo image. If <I>image</I> is + "", no tiling is performed. The default is "". + + <B>-bindtags</B> <I>tagList</I> + Specifies the binding tags for the element. <I>TagList</I> 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 all. + + <B>-color</B> <I>color</I> + Sets the color of the traces connecting the data points. + + <B>-dashes</B> <I>dashList</I> + Sets the dash style of element line. <I>DashList</I> 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 <I>dashList</I> is "", the + lines will be solid. + + <B>-data</B> <I>coordList</I> + Specifies the X-Y coordinates of the data. <I>CoordList</I> is + Sets the element's label in the legend. If <I>text</I> is "", + the element will have no entry in the legend. The + default label is the element's name. + + <B>-linewidth</B> <I>pixels</I> + Sets the width of the connecting lines between data + points. If <I>pixels</I> is 0, no connecting lines will be + drawn between symbols. The default is 0. + + <B>-mapx</B> <I>xAxis</I> + Selects the X-axis to map the element's X-coordinates + onto. <I>XAxis</I> must be the name of an axis. The default is + x. + + <B>-mapy</B> <I>yAxis</I> + Selects the Y-axis to map the element's Y-coordinates + onto. <I>YAxis</I> must be the name of an axis. The default is + y. + + <B>-offdash</B> <I>color</I> + Sets the color of the stripes when traces are dashed (see + the <B>-dashes</B> option). If <I>color</I> is "", then the "off" pix- + els will represent gaps instead of stripes. If <I>color</I> is + defcolor, then the color will be the same as the <B>-color</B> + option. The default is defcolor. + + <B>-outline</B> <I>color</I> + Sets the color or the outline around each symbol. If + <I>color</I> is "", then no outline is drawn. If <I>color</I> is def- + color, then the color will be the same as the <B>-color</B> + option. The default is defcolor. + + <B>-pen</B> <I>penname</I> + Set the pen to use for this element. + + <B>-outlinewidth</B> <I>pixels</I> + Sets the width of the outline bordering each symbol. If + <I>pixels</I> is 0, no outline will be drawn. The default is 1. + + <B>-pixels</B> <I>pixels</I> + Sets the size of symbols. If <I>pixels</I> is 0, no symbols + will be drawn. The default is 0.125i. + + <B>-scalesymbols</B> <I>boolean</I> + If <I>boolean</I> is true, the size of the symbols drawn for + <I>elemName</I> 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 <B>-pixels</B> 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 <I>boolean</I> is + dratic spline is used. The default is <I>linear</I>. + + <B>-styles</B> <I>styleList</I> + Specifies what pen to use based on the range of weights + given. <I>StyleList</I> 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 <B>-weight</B> 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. + + <B>-symbol</B> <I>symbol</I> + Specifies the symbol for data points. <I>Symbol</I> can be + either square, circle, diamond, plus, cross, splus, + scross, triangle, "" (where no symbol is drawn), or a + bitmap. Bitmaps are specified as "<I>source</I> ?<I>mask</I>?", where + <I>source</I> is the name of the bitmap, and <I>mask</I> is the bit- + map's optional mask. The default is circle. + + <B>-trace</B> <I>direction</I> + Indicates whether connecting lines between data points + (whose X-coordinate values are either increasing or + decreasing) are drawn. <I>Direction</I> must be increasing, + decreasing, or both. For example, if <I>direction</I> is + increasing, connecting lines will be drawn only between + those data points where X-coordinate values are monotoni- + cally increasing. If <I>direction</I> is both, connecting lines + will be draw between all data points. The default is + both. + + <B>-weights</B> <I>wVec</I> + Specifies the weights of the individual data points. + This, with the list pen styles (see the <B>-styles</B> option), + controls how data points are drawn. <I>WVec</I> is the name of + a BLT vector or a list of numeric expressions represent- + ing the weights for each data point. + + <B>-xdata</B> <I>xVec</I> + Specifies the X-coordinates of the data. <I>XVec</I> is the + name of a BLT vector or a list of numeric expressions. + + <B>-ydata</B> <I>yVec</I> + Specifies the Y-coordinates of the data. <I>YVec</I> is the + name of a BLT vector or a list of numeric expressions. + + Element configuration options may also be set by the <B>option</B> com- + mand. The resource class is Element. The resource name is the + name of the element. option add *Graph.Element.symbol line + option add *Graph.e1.symbol line + + <I>pathName</I> <B>element</B> <B>exists</B> <I>elemName</I> + Returns 1 if an element <I>elemName</I> currently exists and 0 other- + wise. + + <I>pathName</I> <B>element</B> <B>names</B> ?<I>pattern</I>?... + Returns the elements matching one or more pattern. If no <I>pat-</I> + <I>tern</I> is given, the names of all elements is returned. + + <I>pathName</I> <B>element</B> <B>show</B> ?<I>nameList</I>? + Queries or modifies the element display list. The element dis- + play list designates the elements drawn and in what order. + <I>NameList</I> is a list of elements to be displayed in the order they + are named. If there is no <I>nameList</I> argument, the current dis- + play list is returned. + + <I>pathName</I> <B>element</B> <B>type</B> <I>elemName</I> + Returns the type of <I>elemName</I>. If the element is a bar element, + the commands returns the string "bar", otherwise it returns + "line". + + <B>GRID</B> <B>COMPONENT</B> + Grid lines extend from the major and minor ticks of each axis horizon- + tally or vertically across the plotting area. The following operations + are available for grid lines. + + <I>pathName</I> <B>grid</B> <B>cget</B> <I>option</I> + Returns the current value of the grid line configuration option + given by <I>option</I>. <I>Option</I> may be any option described below for + the grid <B>configure</B> operation. + + <I>pathName</I> <B>grid</B> <B>configure</B> ?<I>option</I> <I>value</I>?... + Queries or modifies the configuration options for grid lines. + If <I>option</I> isn't specified, a list describing all the current + grid options for <I>pathName</I> is returned. If <I>option</I> is specified, + but not <I>value</I>, then a list describing <I>option</I> is returned. If + one or more <I>option</I> and <I>value</I> pairs are specified, then for each + pair, the grid line option <I>option</I> is set to <I>value</I>. The follow- + ing options are valid for grid lines. + + <B>-color</B> <I>color</I> + Sets the color of the grid lines. The default is black. + + <B>-dashes</B> <I>dashList</I> + Sets the dash style of the grid lines. <I>DashList</I> 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 <I>dashList</I> is "", the + grid will be solid lines. + + <B>-hide</B> <I>boolean</I> + Indicates whether the grid should be drawn. If <I>boolean</I> is + + <B>-minor</B> <I>boolean</I> + Indicates whether the grid lines should be drawn for + minor ticks. If <I>boolean</I> is true, the lines will appear + at minor tick intervals. The default is 1. + + Grid configuration options may also be set by the <B>option</B> com- + mand. The resource name and class are grid and Grid respec- + tively. option add *Graph.grid.LineWidth 2 option add + *Graph.Grid.Color black + + <I>pathName</I> <B>grid</B> <B>off</B> + Turns off the display the grid lines. + + <I>pathName</I> <B>grid</B> <B>on</B> + Turns on the display the grid lines. + + <I>pathName</I> <B>grid</B> <B>toggle</B> + Toggles the display of the grid. + + <B>LEGEND</B> <B>COMPONENT</B> + 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 posi- + tioned anywhere within the plotting area. + + The following operations are valid for the legend. + + <I>pathName</I> <B>legend</B> <B>activate</B> <I>pattern</I>... + Selects legend entries to be drawn using the active legend col- + ors and relief. All entries whose element names match <I>pattern</I> + are selected. To be selected, the element name must match only + one <I>pattern</I>. + + <I>pathName</I> <B>legend</B> <B>bind</B> <I>tagName</I> ?<I>sequence</I>? ?<I>command</I>? + Associates <I>command</I> with <I>tagName</I> such that whenever the event + sequence given by <I>sequence</I> occurs for a legend entry with this + tag, <I>command</I> will be invoked. Implicitly the element names in + the entry are tags. The syntax is similar to the <B>bind</B> command + except that it operates on legend entries, rather than widgets. + See the <B>bind</B> manual entry for complete details on <I>sequence</I> and + the substitutions performed on <I>command</I> before invoking it. + + If all arguments are specified then a new binding is created, + replacing any existing binding for the same <I>sequence</I> and <I>tag-</I> + <I>Name</I>. If the first character of <I>command</I> is + then <I>command</I> aug- + ments an existing binding rather than replacing it. If no <I>com-</I> + <I>mand</I> argument is provided then the command currently associated + with <I>tagName</I> and <I>sequence</I> (it's an error occurs if there's no + such binding) is returned. If both <I>command</I> and <I>sequence</I> are + missing then a list of all the event sequences for which bind- + ings have been defined for <I>tagName</I>. + + <B>-activebackground</B> <I>color</I> + Sets the background color for active legend entries. All + legend entries marked active (see the legend <B>activate</B> + operation) are drawn using this background color. + + <B>-activeborderwidth</B> <I>pixels</I> + Sets the width of the 3-D border around the outside edge + of the active legend entries. The default is 2. + + <B>-activeforeground</B> <I>color</I> + Sets the foreground color for active legend entries. All + legend entries marked as active (see the legend <B>activate</B> + operation) are drawn using this foreground color. + + <B>-activerelief</B> <I>relief</I> + Specifies the 3-D effect desired for active legend + entries. <I>Relief</I> denotes how the interior of the entry + should appear relative to the legend; for example, raised + means the entry should appear to protrude from the leg- + end, relative to the surface of the legend. The default + is flat. + + <B>-anchor</B> <I>anchor</I> + Tells how to position the legend relative to the posi- + tioning point for the legend. This is dependent on the + value of the <B>-position</B> option. The default is center. + + left or right + The anchor describes how to position the leg- + end vertically. + + top or bottom + The anchor describes how to position the leg- + end horizontally. + + @x,y The anchor specifies how to position the leg- + end relative to the positioning point. For + example, if <I>anchor</I> is center then the legend + is centered on the point; if <I>anchor</I> is n then + the legend will be drawn such that the top + center point of the rectangular region occu- + pied by the legend will be at the positioning + point. + + plotarea The anchor specifies how to position the leg- + end relative to the plotting area. For exam- + ple, if <I>anchor</I> is center then the legend is + centered in the plotting area; if <I>anchor</I> is + ne then the legend will be drawn such that + occupies the upper right corner of the plot- + ting area. + + Sets the width of the 3-D border around the outside edge + of the legend (if such border is being drawn; the <B>relief</B> + option determines this). The default is 2 pixels. + + <B>-font</B> <I>fontName</I> + <I>FontName</I> specifies a font to use when drawing the labels + of each element into the legend. The default is *-Hel- + vetica-Bold-R-Normal-*-12-120-*. + + <B>-foreground</B> <I>color</I> + Sets the foreground color of the text drawn for the ele- + ment's label. The default is black. + + <B>-hide</B> <I>boolean</I> + Indicates whether the legend should be displayed. If + <I>boolean</I> is true, the legend will not be draw. The + default is no. + + <B>-ipadx</B> <I>pad</I> + Sets the amount of internal padding to be added to the + width of each legend entry. <I>Pad</I> can be a list of one or + two screen distances. If <I>pad</I> has two elements, the left + side of the legend entry is padded by the first distance + and the right side by the second. If <I>pad</I> is just one + distance, both the left and right sides are padded + evenly. The default is 2. + + <B>-ipady</B> <I>pad</I> + Sets an amount of internal padding to be added to the + height of each legend entry. <I>Pad</I> can be a list of one or + two screen distances. If <I>pad</I> has two elements, the top + of the entry is padded by the first distance and the bot- + tom by the second. If <I>pad</I> is just one distance, both the + top and bottom of the entry are padded evenly. The + default is 2. + + <B>-padx</B> <I>pad</I> + Sets the padding to the left and right exteriors of the + legend. <I>Pad</I> can be a list of one or two screen dis- + tances. If <I>pad</I> has two elements, the left side of the + legend is padded by the first distance and the right side + by the second. If <I>pad</I> has just one distance, both the + left and right sides are padded evenly. The default is + 4. + + <B>-pady</B> <I>pad</I> + Sets the padding above and below the legend. <I>Pad</I> can be + a list of one or two screen distances. If <I>pad</I> has two + elements, the area above the legend is padded by the + first distance and the area below by the second. If <I>pad</I> + is just one distance, both the top and bottom areas are + padded evenly. The default is 0. + plotting area. If <I>boolean</I> is true, the legend will be + drawn on top of any elements that may overlap it. The + default is no. + + <B>-relief</B> <I>relief</I> + Specifies the 3-D effect for the border around the leg- + end. <I>Relief</I> specifies how the interior of the legend + should appear relative to the graph; for example, raised + means the legend should appear to protrude from the + graph, relative to the surface of the graph. The default + is sunken. + + Legend configuration options may also be set by the <B>option</B> com- + mand. The resource name and class are legend and Legend respec- + tively. option add *Graph.legend.Foreground blue option add + *Graph.Legend.Relief raised + + <I>pathName</I> <B>legend</B> <B>deactivate</B> <I>pattern</I>... + Selects legend entries to be drawn using the normal legend col- + ors and relief. All entries whose element names match <I>pattern</I> + are selected. To be selected, the element name must match only + one <I>pattern</I>. + + <I>pathName</I> <B>legend</B> <B>get</B> <I>pos</I> + Returns the name of the element whose entry is at the screen + position <I>pos</I> in the legend. <I>Pos</I> must be in the form "<I>@x,y</I>", + where <I>x</I> and <I>y</I> are window coordinates. If the given coordinates + do not lie over a legend entry, "" is returned. + + <B>PEN</B> <B>COMPONENTS</B> + 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 <B>-weight</B> and <B>-style</B> options). + + One pen, called activeLine, 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. .g pen + configure "activeLine" -color green You can create and use several + pens. To create a pen, invoke the pen component and its create opera- + tion. .g pen create myPen You map pens to a data element using either + the element's <B>-pen</B> or <B>-activepen</B> options. .g element create "line1" + -xdata $x -ydata $tempData \ + -pen myPen 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 + <B>-styles</B> option). .g element configure "line1" -styles { myPen 2.0 3.0 + } This says that any data point with a weight between 2.0 and 3.0 is to + be drawn using the pen myPen. All other points are drawn with the ele- + ment's default attributes. + + specified, then for each pair, the pen option <I>option</I> is set to + <I>value</I>. The following options are valid for pens. + + <B>-color</B> <I>color</I> + Sets the color of the traces connecting the data points. + + <B>-dashes</B> <I>dashList</I> + Sets the dash style of element line. <I>DashList</I> 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 <I>dashList</I> is "", the + lines will be solid. + + <B>-fill</B> <I>color</I> + Sets the interior color of symbols. If <I>color</I> is "", then + the interior of the symbol is transparent. If <I>color</I> is + defcolor, then the color will be the same as the <B>-color</B> + option. The default is defcolor. + + <B>-linewidth</B> <I>pixels</I> + Sets the width of the connecting lines between data + points. If <I>pixels</I> is 0, no connecting lines will be + drawn between symbols. The default is 0. + + <B>-offdash</B> <I>color</I> + Sets the color of the stripes when traces are dashed (see + the <B>-dashes</B> option). If <I>color</I> is "", then the "off" pix- + els will represent gaps instead of stripes. If <I>color</I> is + defcolor, then the color will be the same as the <B>-color</B> + option. The default is defcolor. + + <B>-outline</B> <I>color</I> + Sets the color or the outline around each symbol. If + <I>color</I> is "", then no outline is drawn. If <I>color</I> is def- + color, then the color will be the same as the <B>-color</B> + option. The default is defcolor. + + <B>-outlinewidth</B> <I>pixels</I> + Sets the width of the outline bordering each symbol. If + <I>pixels</I> is 0, no outline will be drawn. The default is 1. + + <B>-pixels</B> <I>pixels</I> + Sets the size of symbols. If <I>pixels</I> is 0, no symbols + will be drawn. The default is 0.125i. + + <B>-symbol</B> <I>symbol</I> + Specifies the symbol for data points. <I>Symbol</I> can be + either square, circle, diamond, plus, cross, splus, + scross, triangle, "" (where no symbol is drawn), or a + bitmap. Bitmaps are specified as "<I>source</I> ?<I>mask</I>?", where + <I>source</I> is the name of the bitmap, and <I>mask</I> is the bit- + map's optional mask. The default is circle. + + Creates a new pen by the name <I>penName</I>. No pen by the same name + can already exist. <I>Option</I> and <I>value</I> are described in above in + the pen <B>configure</B> operation. + + <I>pathName</I> <B>pen</B> <B>delete</B> ?<I>penName</I>?... + 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 ele- + ments. + + <I>pathName</I> <B>pen</B> <B>names</B> ?<I>pattern</I>?... + Returns a list of pens matching zero or more patterns. If no + <I>pattern</I> argument is give, the names of all pens are returned. + + <B>POSTSCRIPT</B> <B>COMPONENT</B> + The graph can generate encapsulated PostScript output. There are sev- + eral 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. + + The following postscript operations are available. + + <I>pathName</I> <B>postscript</B> <B>cget</B> <I>option</I> + Returns the current value of the postscript option given by + <I>option</I>. <I>Option</I> may be any option described below for the post- + script <B>configure</B> operation. + + <I>pathName</I> <B>postscript</B> <B>configure</B> ?<I>option</I> <I>value</I>?... + Queries or modifies the configuration options for PostScript + generation. If <I>option</I> isn't specified, a list describing the + current postscript options for <I>pathName</I> is returned. If <I>option</I> + is specified, but not <I>value</I>, then a list describing <I>option</I> is + returned. If one or more <I>option</I> and <I>value</I> pairs are specified, + then for each pair, the postscript option <I>option</I> is set to + <I>value</I>. The following postscript options are available. + + <B>-center</B> <I>boolean</I> + Indicates whether the plot should be centered on the + PostScript page. If <I>boolean</I> is false, the plot will be + placed in the upper left corner of the page. The default + is 1. + + <B>-colormap</B> <I>varName</I> + <I>VarName</I> must be the name of a global array variable that + specifies a color mapping from the X color name to Post- + Script. Each element of <I>varName</I> must consist of Post- + Script code to set a particular color value (e.g. ``1.0 + 1.0 0.0 setrgbcolor''). When generating color informa- + tion in PostScript, the array variable <I>varName</I> 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 + Script. Each element of <I>varName</I> 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 <I>varName</I> 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). Other- + wise the X font is examined in an attempt to guess what + PostScript font to use. This works only for fonts whose + foundry property is <I>Adobe</I> (such as Times, Helvetica, + Courier, etc.). If all of this fails then the font + defaults to Helvetica-Bold. + + <B>-decorations</B> <I>boolean</I> + Indicates whether PostScript commands to generate color + backgrounds and 3-D borders will be output. If <I>boolean</I> + is false, the background will be white and no 3-D borders + will be generated. The default is 1. + + <B>-height</B> <I>pixels</I> + Sets the height of the plot. This lets you print the + graph with a height different from the one drawn on the + screen. If <I>pixels</I> is 0, the height is the same as the + widget's height. The default is 0. + + <B>-landscape</B> <I>boolean</I> + If <I>boolean</I> 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 (``land- + scape'' orientation). Defaults to 0. + + <B>-maxpect</B> <I>boolean</I> + Indicates to scale the plot so that it fills the Post- + Script page. The aspect ratio of the graph is still + retained. The default is 0. + + <B>-padx</B> <I>pad</I> + Sets the horizontal padding for the left and right page + borders. The borders are exterior to the plot. <I>Pad</I> can + be a list of one or two screen distances. If <I>pad</I> has two + elements, the left border is padded by the first distance + and the right border by the second. If <I>pad</I> has just one + distance, both the left and right borders are padded + evenly. The default is 1i. + + <B>-pady</B> <I>pad</I> + Sets the vertical padding for the top and bottom page + borders. The borders are exterior to the plot. <I>Pad</I> can + The default width is 8.5i. + + <B>-width</B> <I>pixels</I> + Sets the width of the plot. This lets you generate a + plot of a width different from that of the widget. If + <I>pixels</I> is 0, the width is the same as the widget's width. + The default is 0. + + Postscript configuration options may be also be set by the + <B>option</B> command. The resource name and class are postscript and + Postscript respectively. option add *Graph.postscript.Decora- + tions false option add *Graph.Postscript.Landscape true + + <I>pathName</I> <B>postscript</B> <B>output</B> ?<I>fileName</I>? ?<I>option</I> <I>value</I>?... + Outputs a file of encapsulated PostScript. If a <I>fileName</I> argu- + ment isn't present, the command returns the PostScript. If any + <I>option-value</I> pairs are present, they set configuration options + controlling how the PostScript is generated. <I>Option</I> and <I>value</I> + can be anything accepted by the postscript <B>configure</B> operation + above. + + <B>MARKER</B> <B>COMPONENTS</B> + 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 <B>-under</B> option. + + Markers, in contrast to elements, don't affect the scaling of the coor- + dinate axes. They can also have <I>elastic</I> coordinates (specified by -Inf + and Inf 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 + -Inf,-Inf. + + The following operations are available for markers. + + <I>pathName</I> <B>marker</B> <B>after</B> <I>markerId</I> ?<I>afterId</I>? + Changes the order of the markers, drawing the first marker after + the second. If no second <I>afterId</I> 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. + + <I>pathName</I> <B>marker</B> <B>before</B> <I>markerId</I> ?<I>beforeId</I>? + Changes the order of the markers, drawing the first marker + before the second. If no second <I>beforeId</I> 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. + with <I>tagName</I> and <I>sequence</I> (it's an error occurs if there's no + such binding) is returned. If both <I>command</I> and <I>sequence</I> are + missing then a list of all the event sequences for which bind- + ings have been defined for <I>tagName</I>. + + <I>pathName</I> <B>marker</B> <B>cget</B> <I>option</I> + Returns the current value of the marker configuration option + given by <I>option</I>. <I>Option</I> may be any option described below in + the <B>configure</B> operation. + + <I>pathName</I> <B>marker</B> <B>configure</B> <I>markerId</I> ?<I>option</I> <I>value</I>?... + Queries or modifies the configuration options for markers. If + <I>option</I> isn't specified, a list describing the current options + for <I>markerId</I> is returned. If <I>option</I> is specified, but not + <I>value</I>, then a list describing <I>option</I> is returned. If one or + more <I>option</I> and <I>value</I> pairs are specified, then for each pair, + the marker option <I>option</I> is set to <I>value</I>. + + 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. + + <B>-bindtags</B> <I>tagList</I> + Specifies the binding tags for the marker. <I>TagList</I> 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 all. + + <B>-coords</B> <I>coordList</I> + Specifies the coordinates of the marker. <I>CoordList</I> 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 <I>coordList</I> is "", the marker + will not be displayed. The default is "". + + <B>-element</B> <I>elemName</I> + Links the marker with the element <I>elemName</I>. The marker + is drawn only if the element is also currently displayed + (see the element's <B>show</B> operation). If <I>elemName</I> is "", + the marker is always drawn. The default is "". + + <B>-hide</B> <I>boolean</I> + Indicates whether the marker is drawn. If <I>boolean</I> is + true, the marker is not drawn. The default is no. + + <B>-under</B> <I>boolean</I> + Indicates whether the marker is drawn below/above data + elements. If <I>boolean</I> is true, the marker is be drawn + underneath the data element symbols and lines. Other- + wise, the marker is drawn on top of the element. The + default is 0. + + <B>-xoffset</B> <I>pixels</I> + Specifies a screen distance to offset the marker horizon- + tally. <I>Pixels</I> is a valid screen distance, such as 2 or + 1.2i. The default is 0. + + <B>-yoffset</B> <I>pixels</I> + Specifies a screen distance to offset the markers verti- + cally. <I>Pixels</I> is a valid screen distance, such as 2 or + 1.2i. The default is 0. + + Marker configuration options may also be set by the <B>option</B> com- + mand. The resource class is either BitmapMarker, ImageMarker, + LineMarker, PolygonMarker, TextMarker, or WindowMarker, depend- + ing on the type of marker. The resource name is the name of the + marker. option add *Graph.TextMarker.Foreground white option + add *Graph.BitmapMarker.Foreground white option add + *Graph.m1.Background blue + + <I>pathName</I> <B>marker</B> <B>create</B> <I>type</I> ?<I>option</I> <I>value</I>?... + Creates a marker of the selected type. <I>Type</I> may be either text, + line, bitmap, image, polygon, or window. This command returns + the marker identifier, used as the <I>markerId</I> argument in the + other marker-related commands. If the <B>-name</B> option is used, + this overrides the normal marker identifier. If the name pro- + vided is already used for another marker, the new marker will + replace the old. + + <I>pathName</I> <B>marker</B> <B>delete</B> ?<I>name</I>?... + Removes one of more markers. The graph will automatically be + redrawn without the marker.. + + <I>pathName</I> <B>marker</B> <B>exists</B> <I>markerId</I> + Returns 1 if the marker <I>markerId</I> exists and 0 otherwise. + + <I>pathName</I> <B>marker</B> <B>names</B> ?<I>pattern</I>? + Returns the names of all the markers that currently exist. If + <I>pattern</I> is supplied, only those markers whose names match it + will be returned. + + <I>pathName</I> <B>marker</B> <B>type</B> <I>markerId</I> + Returns the type of the marker given by <I>markerId</I>, such as line + or text. If <I>markerId</I> is not a valid a marker identifier, "" is + returned. + + <B>BITMAP</B> <B>MARKERS</B> + The following options are specific to bitmap markers: + + <B>-background</B> <I>color</I> + Same as the <B>-fill</B> option. + + <B>-bitmap</B> <I>bitmap</I> + Specifies the bitmap to be displayed. If <I>bitmap</I> is "", the + marker will not be displayed. The default is "". + + <B>-fill</B> <I>color</I> + Sets the background color of the bitmap. If <I>color</I> is the empty + string, no background will be transparent. The default back- + ground color is "". + + <B>-foreground</B> <I>color</I> + Same as the <B>-outline</B> option. + + <B>-mask</B> <I>mask</I> + Specifies a mask for the bitmap to be displayed. This mask is a + bitmap itself, denoting the pixels that are transparent. If + <I>mask</I> is "", all pixels of the bitmap will be drawn. The default + is "". + + <B>-outline</B> <I>color</I> + Sets the foreground color of the bitmap. The default value is + black. + + <B>-rotate</B> <I>theta</I> + Sets the rotation of the bitmap. <I>Theta</I> is a real number repre- + senting the angle of rotation in degrees. The marker is first + rotated and then placed according to its anchor position. The + default rotation is 0.0. + + <B>IMAGE</B> <B>MARKERS</B> + A image marker displays an image. Image markers are created with the + marker's <B>create</B> operation in the form: <I>pathName</I> <B>marker</B> <B>create</B> <B>image</B> + ?<I>option</I> <I>value</I>?... There may be many <I>option</I>-<I>value</I> pairs, each sets a + configuration option for the marker. These same <I>option</I>-<I>value</I> pairs may + be used with the marker's <B>configure</B> operation. + + The following options are specific to image markers: + + <B>-anchor</B> <I>anchor</I> + <I>Anchor</I> tells how to position the image relative to the position- + ing point for the image. For example, if <I>anchor</I> is center then + the image is centered on the point; if <I>anchor</I> is n then the + image will be drawn such that the top center point of the rect- + angular region occupied by the image will be at the positioning + point. This option defaults to center. + + <B>-image</B> <I>image</I> + Specifies the image to be drawn. If <I>image</I> is "", the marker + gaps on the line. Each number must be between 1 and 255. If + <I>dashList</I> is "", the marker line will be solid. + + <B>-fill</B> <I>color</I> + Sets the background color of the line. This color is used with + striped lines (see the <B>-fdashes</B> option). If <I>color</I> is the empty + string, no background color is drawn (the line will be dashed, + not striped). The default background color is "". + + <B>-linewidth</B> <I>pixels</I> + Sets the width of the lines. The default width is 0. + + <B>-outline</B> <I>color</I> + Sets the foreground color of the line. The default value is + black. + + <B>-stipple</B> <I>bitmap</I> + Specifies a stipple pattern used to draw the line, rather than a + solid line. <I>Bitmap</I> specifies a bitmap to use as the stipple + pattern. If <I>bitmap</I> is "", then the line is drawn in a solid + fashion. The default is "". + + <B>POLYGON</B> <B>MARKERS</B> + A polygon marker displays a closed region described as two or more con- + nected line segments. It is assumed the first and last points are con- + nected. Polygon markers are created using the marker <B>create</B> operation + in the form: <I>pathName</I> <B>marker</B> <B>create</B> <B>polygon</B> ?<I>option</I> <I>value</I>?... There + may be many <I>option</I>-<I>value</I> pairs, each sets a configuration option for + the marker. These same <I>option</I>-<I>value</I> pairs may be used with the <B>marker</B> + <B>configure</B> command to change the marker's configuration. The following + options are supported for polygon markers: + + <B>-dashes</B> <I>dashList</I> + Sets the dash style of the outline of the polygon. <I>DashList</I> 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 <I>dashList</I> is "", the outline will be a + solid line. + + <B>-fill</B> <I>color</I> + Sets the fill color of the polygon. If <I>color</I> is "", then the + interior of the polygon is transparent. The default is white. + + <B>-linewidth</B> <I>pixels</I> + Sets the width of the outline of the polygon. If <I>pixels</I> is zero, + no outline is drawn. The default is 0. + + <B>-outline</B> <I>color</I> + Sets the color of the outline of the polygon. If the polygon is + stippled (see the <B>-stipple</B> option), then this represents the + foreground color of the stipple. The default is black. + + the marker's <B>configure</B> operation. + + The following options are specific to text markers: + + <B>-anchor</B> <I>anchor</I> + <I>Anchor</I> tells how to position the text relative to the position- + ing point for the text. For example, if <I>anchor</I> is center then + the text is centered on the point; if <I>anchor</I> is n 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 center. + + <B>-background</B> <I>color</I> + Same as the <B>-fill</B> option. + + <B>-font</B> <I>fontName</I> + Specifies the font of the text. The default is *-Helvetica- + Bold-R-Normal-*-120-*. + + <B>-fill</B> <I>color</I> + Sets the background color of the text. If <I>color</I> is the empty + string, no background will be transparent. The default back- + ground color is "". + + <B>-foreground</B> <I>color</I> + Same as the <B>-outline</B> option. + + <B>-justify</B> <I>justify</I> + Specifies how the text should be justified. This matters only + when the marker contains more than one line of text. <I>Justify</I> + must be left, right, or center. The default is center. + + <B>-outline</B> <I>color</I> + Sets the color of the text. The default value is black. + + <B>-padx</B> <I>pad</I> + Sets the padding to the left and right exteriors of the text. + <I>Pad</I> can be a list of one or two screen distances. If <I>pad</I> has + two elements, the left side of the text is padded by the first + distance and the right side by the second. If <I>pad</I> has just one + distance, both the left and right sides are padded evenly. The + default is 4. + + <B>-pady</B> <I>pad</I> + Sets the padding above and below the text. <I>Pad</I> can be a list of + one or two screen distances. If <I>pad</I> has two elements, the area + above the text is padded by the first distance and the area + below by the second. If <I>pad</I> is just one distance, both the top + and bottom areas are padded evenly. The default is 4. + + <B>-rotate</B> <I>theta</I> + Specifies the number of degrees to rotate the text. <I>Theta</I> is a + + <I>option</I>-<I>value</I> pairs may be used with the marker's <B>configure</B> command. + + The following options are specific to window markers: + + <B>-anchor</B> <I>anchor</I> + <I>Anchor</I> tells how to position the widget relative to the posi- + tioning point for the widget. For example, if <I>anchor</I> is center + then the widget is centered on the point; if <I>anchor</I> is n 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 center. + + <B>-height</B> <I>pixels</I> + Specifies the height to assign to the marker's window. If this + option isn't specified, or if it is specified as "", then the + window is given whatever height the widget requests internally. + + <B>-width</B> <I>pixels</I> + Specifies the width to assign to the marker's window. If this + option isn't specified, or if it is specified as "", then the + window is given whatever width the widget requests internally. + + <B>-window</B> <I>pathName</I> + Specifies the widget to be managed by the graph. <I>PathName</I> must + be a child of the <B>graph</B> widget. + + +</PRE> +<H2>GRAPH COMPONENT BINDINGS</H2><PRE> + 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 <B>Enter</B>, <B>Leave</B>, <B>ButtonPress</B>, <B>Motion</B>, + and <B>KeyPress</B>). + + 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 com- + mands will be invoked if both items are picked. + + 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 + <B>-bindtags</B> 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 com- + mand. + + vectors are updated. + + From Tcl, create the vectors and configure the element to use them. + vector X Y .g element configure line1 -xdata X -ydata Y To set data + points from C, you pass the values as arrays of doubles using the + <B>Blt_ResetVector</B> 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. #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; } See the <B>vector</B> manual page for more details. + + +</PRE> +<H2>SPEED TIPS</H2><PRE> + 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. + + <B>o</B> Try to minimize the number of data points. The more data points the + looked at, the more work the graph must do. + + <B>o</B> If your data is generated as floating point values, the time required + to convert the data values to and from ASCII strings can be signifi- + cant, especially when there any many data points. You can avoid the + redundant string-to-decimal conversions using the C API to BLT vec- + tors. + + <B>o</B> Data elements without symbols are drawn faster than with symbols. + Set the data element's <B>-symbol</B> option to none. If you need to draw + symbols, try using the simple symbols such as splus and scross. + + <B>o</B> Don't stipple or dash the element. Solid lines are much faster. + + <B>o</B> If you update data elements frequently, try turning off the widget's + <B>-bufferelements</B> 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 ele- + ments 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 + + + +BLT BLT_VERSION graph(n) +</PRE> +<HR> +<ADDRESS> +Man(1) output converted with +<a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a> +</ADDRESS> +</BODY> +</HTML> |