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<HTML>
<BODY>
<PRE>
<!-- Manpage converted by man2html 3.0.1 -->
</PRE>
<H2>SYNOPSIS</H2><PRE>
<B>blt::vector</B> <B>create</B> <I>vecName</I> ?<I>vecName</I>...? ?<I>switches</I>?
<B>blt::vector</B> <B>destroy</B> <I>vecName</I> ?<I>vecName</I>...?
<B>blt::vector</B> <B>expr</B> <I>expression</I>
<B>blt::vector</B> <B>names</B> ?<I>pattern</I>...?
</PRE>
<H2>DESCRIPTION</H2><PRE>
The <B>vector</B> command creates an array of floating point values. The vec-
tor's components can be manipulated in three ways: through a Tcl array
variable, a Tcl command, or the C API.
</PRE>
<H2>INTRODUCTION</H2><PRE>
A vector is an ordered set of real numbers. The components of a vector
are indexed by integers.
Vectors are common data structures for many applications. For example,
a graph may use two vectors to represent the X-Y coordinates of the
data plotted. The graph will automatically be redrawn when the vectors
are updated or changed. By using vectors, you can separate data analy-
sis from the graph widget. This makes it easier, for example, to add
data transformations, such as splines. It's possible to plot the same
data to in multiple graphs, where each graph presents a different view
or scale of the data.
You could try to use Tcl's associative arrays as vectors. Tcl arrays
are easy to use. You can access individual elements randomly by speci-
fying the index, or the set the entire array by providing a list of
index and value pairs for each element. The disadvantages of associa-
tive arrays as vectors lie in the fact they are implemented as hash
tables.
<B>o</B> There's no implied ordering to the associative arrays. If you used
vectors for plotting, you would want to insure the second component
comes after the first, an so on. This isn't possible since arrays
are actually hash tables. For example, you can't get a range of val-
ues between two indices. Nor can you sort an array.
<B>o</B> Arrays consume lots of memory when the number of elements becomes
large (tens of thousands). This is because each element's index and
value are stored as strings in the hash table.
<B>o</B> The C programming interface is unwieldy. Normally with vectors, you
would like to view the Tcl array as you do a C array, as an array of
floats or doubles. But with hash tables, you must convert both the
index and value to and from decimal strings, just to access an ele-
ment in the array. This makes it cumbersome to perform operations on
the array as a whole.
The <B>vector</B> command tries to overcome these disadvantages while still
0.0. In addition, both a Tcl command and array variable, both named y,
are created. You can use either the command or variable to query or
modify components of the vector. # Set the first value. set <B>y(0)</B> 9.25
puts "y has [y length] components" The array y can be used to read or
set individual components of the vector. Vector components are indexed
from zero. The array index must be a number less than the number of
components. For example, it's an error if you try to set the 51st ele-
ment of y. # This is an error. The vector only has 50 components. set
<B>y(50)</B> 0.02 You can also specify a range of indices using a colon (:) to
separate the first and last indices of the range. # Set the first six
components of y set y(0:5) 25.2 If you don't include an index, then it
will default to the first and/or last component of the vector. # Print
out all the components of y puts "y = $y(:)" There are special non-
numeric indices. The index end, specifies the last component of the
vector. It's an error to use this index if the vector is empty (length
is zero). The index ++end can be used to extend the vector by one com-
ponent and initialize it to a specific value. You can't read from the
array using this index, though. # Extend the vector by one component.
set y(++end) 0.02 The other special indices are min and max. They
return the current smallest and largest components of the vector. #
Print the bounds of the vector puts "min=$y(min) max=$y(max)" To delete
components from a vector, simply unset the corresponding array element.
In the following example, the first component of y is deleted. All the
remaining components of y will be moved down by one index as the length
of the vector is reduced by one. # Delete the first component unset
<B>y(0)</B> puts "new first element is $<B>y(0)</B>" The vector's Tcl command can
also be used to query or set the vector. # Create and set the compo-
nents of a new vector blt::vector create x x set { 0.02 0.04 0.06 0.08
0.10 0.12 0.14 0.16 0.18 0.20 } Here we've created a vector x without a
initial length specification. In this case, the length is zero. The
<B>set</B> operation resets the vector, extending it and setting values for
each new component.
There are several operations for vectors. The <B>range</B> operation lists
the components of a vector between two indices. # List the components
puts "x = [x range 0 end]" You can search for a particular value using
the <B>search</B> operation. It returns a list of indices of the components
with the same value. If no component has the same value, it returns
"". # Find the index of the biggest component set indices [x search
$x(max)] Other operations copy, append, or sort vectors. You can
append vectors or new values onto an existing vector with the <B>append</B>
operation. # Append assorted vectors and values to x x append x2 x3 {
2.3 4.5 } x4 The <B>sort</B> operation sorts the vector. If any additional
vectors are specified, they are rearranged in the same order as the
vector. For example, you could use it to sort data points represented
by x and y vectors. # Sort the data points x sort y The vector x is
sorted while the components of y are rearranged so that the original
x,y coordinate pairs are retained.
The <B>expr</B> operation lets you perform arithmetic on vectors. The result
is stored in the vector. # Add the two vectors and a scalar x expr { x
+ y } x expr { x * 2 } When a vector is modified, resized, or deleted,
Vectors are created using the <B>vector</B> <B>create</B> operation. Th <B>create</B> oper-
ation can be invoked in one of three forms:
<B>blt::vector</B> <B>create</B> <I>vecName</I>
This creates a new vector <I>vecName</I> which initially has no compo-
nents.
<B>blt::vector</B> <B>create</B> <I>vecName</I>(<I>size</I>)
This second form creates a new vector which will contain <I>size</I>
number of components. The components will be indexed starting
from zero (0). The default value for the components is 0.0.
<B>blt::vector</B> <B>create</B> <I>vecName</I>(<I>first</I>:<I>last</I>)
The last form creates a new vector of indexed <I>first</I> through
<I>last</I>. <I>First</I> and <I>last</I> can be any integer value so long as <I>first</I>
is less than <I>last</I>.
Vector names must start with a letter and consist of letters, digits,
or underscores. # Error: must start with letter blt::vector create
1abc You can automatically generate vector names using the "#auto" vec-
tor name. The <B>create</B> operation will generate a unique vector name.
set vec [blt::vector create #auto] puts "$vec has [$vec length] compo-
nents"
<B>VECTOR</B> <B>INDICES</B>
Vectors are indexed by integers. You can access the individual vector
components via its array variable or Tcl command. The string repre-
senting the index can be an integer, a numeric expression, a range, or
a special keyword.
The index must lie within the current range of the vector, otherwise an
an error message is returned. Normally the indices of a vector are
start from 0. But you can use the <B>offset</B> operation to change a vec-
tor's indices on-the-fly. puts $<B>vecName(0)</B> vecName offset -5 puts
$vecName(-5) You can also use numeric expressions as indices. The
result of the expression must be an integer value. set n 21 set vec-
Name($n+3) 50.2 The following special non-numeric indices are avail-
able: min, max, end, and ++end. puts "min = $vecName($min)" set vec-
Name(end) -1.2 The indices min and max will return the minimum and max-
imum values of the vector. The index end returns the value of the last
component in the vector. The index ++end is used to append new value
onto the vector. It automatically extends the vector by one component
and sets its value. # Append an new component to the end set vec-
Name(++end) 3.2 A range of indices can be indicated by a colon (:). #
Set the first six components to 1.0 set vecName(0:5) 1.0 If no index is
supplied the first or last component is assumed. # Print the values of
all the components puts $vecName(:)
</PRE>
<H2>VECTOR OPERATIONS</H2><PRE>
<B>blt::vector</B> <B>create</B> <I>vecName</I>?(<I>size</I>)?... ?<I>switches</I>?
The <B>create</B> operation creates a new vector <I>vecName</I>. Both a Tcl
command and array variable <I>vecName</I> are also created. The name
then no variable will be mapped. You can always map a
variable back to the vector using the vector's <B>variable</B>
operation.
<B>-command</B> <I>cmdName</I>
Maps a Tcl command to the vector. The vector can be
accessed using <I>cmdName</I> and one of the vector instance
operations. A Tcl command by that name cannot already
exist. If <I>cmdName</I> is the empty string, no command map-
ping will be made.
<B>-watchunset</B> <I>boolean</I>
Indicates that the vector should automatically delete
itself if the variable associated with the vector is
unset. By default, the vector will not be deleted. This
is different from previous releases. Set <I>boolean</I> to
"true" to get the old behavior.
<B>blt::vector</B> <B>destroy</B> <I>vecName</I> ?<I>vecName...</I>?
Deletes one or more vectors. Both the Tcl command and array
variable are removed also.
<B>blt::vector</B> <B>expr</B> <I>expression</I>
All binary operators take vectors as operands (remember that
numbers are treated as one-component vectors). The exact action
of binary operators depends upon the length of the second oper-
and. If the second operand has only one component, then each
element of the first vector operand is computed by that value.
For example, the expression "x * 2" multiples all elements of
the vector x by 2. If the second operand has more than one com-
ponent, both operands must be the same length. Each pair of
corresponding elements are computed. So "x + y" adds the the
first components of x and y together, the second, and so on.
The valid operators are listed below, grouped in decreasing
order of precedence:
<B>-</B> <B>!</B> Unary minus and logical NOT. The unary
minus flips the sign of each component in
the vector. The logical not operator
returns a vector of whose values are 0.0 or
1.0. For each non-zero component 1.0 is
returned, 0.0 otherwise.
<B>^</B> Exponentiation.
<B>*</B> <B>/</B> <B>%</B> Multiply, divide, remainder.
<B>+</B> <B>-</B> Add and subtract.
<B><<</B> <B>>></B> Left and right shift. Circularly shifts the
values of the vector (not implemented yet).
<B>&&</B> Logical AND. Produces a 1 result if both
operands are non-zero, 0 otherwise.
<B>||</B> Logical OR. Produces a 0 result if both op-
erands are zero, 1 otherwise.
<I>x</I><B>?</B><I>y</I><B>:</B><I>z</I> If-then-else, as in C. (Not implemented
yet).
See the C manual for more details on the results produced by
each operator. All of the binary operators group left-to-right
within the same precedence level.
Several mathematical functions are supported for vectors. Each
of the following functions invokes the math library function of
the same name; see the manual entries for the library functions
for details on what they do. The operation is applied to all
elements of the vector returning the results.
<B>acos</B> <B>cos</B> <B>hypot</B> <B>sinh</B> <B>asin</B> <B>cosh</B> <B>log</B> <B>sqrt</B>
<B>atan</B> <B>exp</B> <B>log10</B> <B>tan</B> <B>ceil</B> <B>floor</B> <B>sin</B> <B>tanh</B>
Additional functions are:
<B>abs</B> Returns the absolute value of each component.
<B>random</B> Returns a vector of non-negative values uniformly dis-
tributed between [0.0, 1.0) using <I>drand48</I>. The seed
comes from the internal clock of the machine or may be
set manual with the srandom function.
<B>round</B> Rounds each component of the vector.
<B>srandom</B> Initializes the random number generator using <I>srand48</I>.
The high order 32-bits are set using the integral por-
tion of the first vector component. All other compo-
nents are ignored. The low order 16-bits are set to
an arbitrary value.
The following functions return a single value.
<B>adev</B> Returns the average deviation (defined as the sum of
the absolute values of the differences between compo-
nent and the mean, divided by the length of the vec-
tor).
<B>kurtosis</B> Returns the degree of peakedness (fourth moment) of
the vector.
<B>length</B> Returns the number of components in the vector.
<B>max</B> Returns the vector's maximum value.
<B>skew</B> Returns the skewness (or third moment) of the vector.
This characterizes the degree of asymmetry of the vec-
tor about the mean.
<B>sum</B> Returns the sum of the components.
<B>var</B> Returns the variance of the vector. The sum of the
squared differences between each component and the
mean is computed. The variance is the sum divided by
the length of the vector minus 1.
The last set returns a vector of the same length as the argu-
ment.
<B>norm</B> Scales the values of the vector to lie in the range
[0.0..1.0].
<B>sort</B> Returns the vector components sorted in ascending
order.
<B>vector</B> <B>names</B> ?<I>pattern</I>?
</PRE>
<H2>INSTANCE OPERATIONS</H2><PRE>
You can also use the vector's Tcl command to query or modify it. The
general form is <I>vecName</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 vectors are listed below.
<I>vecName</I> <B>append</B> <I>item</I> ?<I>item</I>?...
Appends the component values from <I>item</I> to <I>vecName</I>. <I>Item</I> can be
either the name of a vector or a list of numeric values.
<I>vecName</I> <B>binread</B> <I>channel</I> ?<I>length</I>? ?<I>switches</I>?
Reads binary values from a Tcl channel. Values are either
appended to the end of the vector or placed at a given index
(using the <B>-at</B> option), overwriting existing values. Data is
read until EOF is found on the channel or a specified number of
values <I>length</I> are read (note that this is not necessarily the
same as the number of bytes). The following switches are sup-
ported:
<B>-swap</B> Swap bytes and words. The default endian is the host
machine.
<B>-at</B> <I>index</I>
New values will start at vector index <I>index</I>. This will
overwrite any current values.
<B>-format</B> <I>format</I>
Specifies the format of the data. <I>Format</I> can be one of
the following: "i1", "i2", "i4", "i8", "u1, "u2", "u4",
This is useful when the vector is large.
<I>vecName</I> <B>delete</B> <I>index</I> ?<I>index</I>?...
Deletes the <I>index</I>th component from the vector <I>vecName</I>. <I>Index</I> is
the index of the element to be deleted. This is the same as
unsetting the array variable element <I>index</I>. The vector is com-
pacted after all the indices have been deleted.
<I>vecName</I> <B>dup</B> <I>destName</I>
Copies <I>vecName</I> to <I>destName</I>. <I>DestName</I> is the name of a destina-
tion vector. If a vector <I>destName</I> already exists, it is over-
written with the components of <I>vecName</I>. Otherwise a new vector
is created.
<I>vecName</I> <B>expr</B> <I>expression</I>
Computes the expression and resets the values of the vector
accordingly. Both scalar and vector math operations are
allowed. All values in expressions are either real numbers or
names of vectors. All numbers are treated as one component vec-
tors.
<I>vecName</I> <B>length</B> ?<I>newSize</I>?
Queries or resets the number of components in <I>vecName</I>. <I>NewSize</I>
is a number specifying the new size of the vector. If <I>newSize</I>
is smaller than the current size of <I>vecName</I>, <I>vecName</I> is trun-
cated. If <I>newSize</I> is greater, the vector is extended and the
new components are initialized to 0.0. If no <I>newSize</I> argument
is present, the current length of the vector is returned.
<I>vecName</I> <B>merge</B> <I>srcName</I> ?<I>srcName</I>?...
Merges the named vectors into a single vector. The resulting
vector is formed by merging the components of each source vector
one index at a time.
<I>vecName</I> <B>notify</B> <I>keyword</I>
Controls how vector clients are notified of changes to the vec-
tor. The exact behavior is determined by <I>keyword</I>.
always Indicates that clients are to be notified immediately
whenever the vector is updated.
never Indicates that no clients are to be notified.
whenidle
Indicates that clients are to be notified at the next
idle point whenever the vector is updated.
now If any client notifications is currently pending, they
are notified immediately.
cancel Cancels pending notifications of clients using the vec-
tor.
<I>density</I> number of new components, whose values are evenly dis-
tributed between the original components values. This is useful
for generating abscissas to be interpolated along a spline.
<I>vecName</I> <B>range</B> <I>firstIndex</I> ?<I>lastIndex</I>?...
Returns a list of numeric values representing the vector compo-
nents between two indices. Both <I>firstIndex</I> and <I>lastIndex</I> are
indices representing the range of components to be returned. If
<I>lastIndex</I> is less than <I>firstIndex</I>, the components are listed in
reverse order.
<I>vecName</I> <B>search</B> <I>value</I> ?<I>value</I>?
Searches for a value or range of values among the components of
<I>vecName</I>. If one <I>value</I> argument is given, a list of indices of
the components which equal <I>value</I> is returned. If a second <I>value</I>
is also provided, then the indices of all components which lie
within the range of the two values are returned. If no compo-
nents are found, then "" is returned.
<I>vecName</I> <B>set</B> <I>item</I>
Resets the components of the vector to <I>item</I>. <I>Item</I> can be either
a list of numeric expressions or another vector.
<I>vecName</I> <B>seq</B> <I>start</I> ?<I>finish</I>? ?<I>step</I>?
Generates a sequence of values starting with the value <I>start</I>.
<I>Finish</I> indicates the terminating value of the sequence. The
vector is automatically resized to contain just the sequence.
If three arguments are present, <I>step</I> designates the interval.
With only two arguments (no <I>finish</I> argument), the sequence will
continue until the vector is filled. With one argument, the
interval defaults to 1.0.
<I>vecName</I> <B>sort</B> ?<B>-reverse</B>? ?<I>argName</I>?...
Sorts the vector <I>vecName</I> in increasing order. If the <B>-reverse</B>
flag is present, the vector is sorted in decreasing order. If
other arguments <I>argName</I> are present, they are the names of vec-
tors which will be rearranged in the same manner as <I>vecName</I>.
Each vector must be the same length as <I>vecName</I>. You could use
this to sort the x vector of a graph, while still retaining the
same x,y coordinate pairs in a y vector.
<I>vecName</I> <B>variable</B> <I>varName</I>
Maps a Tcl variable to the vector, creating another means for
accessing the vector. The variable <I>varName</I> can't already exist.
This overrides any current variable mapping the vector may have.
</PRE>
<H2>C LANGUAGE API</H2><PRE>
You can create, modify, and destroy vectors from C code, using library
routines. You need to include the header file blt.h. It contains the
definition of the structure <B>Blt_Vector</B>, which represents the vector.
It appears below. typedef struct {
<B>Blt_CreateVector</B>
Synopsis: int <B>Blt_CreateVector</B> (<I>interp</I>, <I>vecName</I>, <I>length</I>, <I>vecPtrPtr</I>)
Tcl_Interp *<I>interp</I>; char *<I>vecName</I>; int <I>length</I>; Blt_Vec-
tor **<I>vecPtrPtr</I>;
Description:
Creates a new vector <I>vecName</I> with a length of <I>length</I>.
<B>Blt_CreateVector</B> creates both a new Tcl command and array
variable <I>vecName</I>. Neither a command nor variable named
<I>vecName</I> can already exist. A pointer to the vector is
placed into <I>vecPtrPtr</I>.
Results: Returns TCL_OK if the vector is successfully created. If
<I>length</I> is negative, a Tcl variable or command <I>vecName</I>
already exists, or memory cannot be allocated for the vec-
tor, then TCL_ERROR is returned and <I>interp->result</I> will
contain an error message.
<B>Blt_DeleteVectorByName</B>
Synopsis: int <B>Blt_DeleteVectorByName</B> (<I>interp</I>, <I>vecName</I>)
Tcl_Interp *<I>interp</I>; char *<I>vecName</I>;
Description:
Removes the vector <I>vecName</I>. <I>VecName</I> is the name of a vec-
tor which must already exist. Both the Tcl command and
array variable <I>vecName</I> are destroyed. All clients of the
vector will be notified immediately that the vector has
been destroyed.
Results: Returns TCL_OK if the vector is successfully deleted. If
<I>vecName</I> is not the name a vector, then TCL_ERROR is
returned and <I>interp->result</I> will contain an error message.
<B>Blt_DeleteVector</B>
Synopsis: int <B>Blt_DeleteVector</B> (<I>vecPtr</I>)
Blt_Vector *<I>vecPtr</I>;
Description:
Removes the vector pointed to by <I>vecPtr</I>. <I>VecPtr</I> is a
pointer to a vector, typically set by <B>Blt_GetVector</B> or
<B>Blt_CreateVector</B>. Both the Tcl command and array variable
of the vector are destroyed. All clients of the vector
will be notified immediately that the vector has been
destroyed.
Results: Returns TCL_OK if the vector is successfully deleted. If
<I>vecName</I> is not the name a vector, then TCL_ERROR is
Results: Returns TCL_OK if the vector is successfully retrieved. If
<I>vecName</I> is not the name of a vector, then TCL_ERROR is
returned and <I>interp->result</I> will contain an error message.
<B>Blt_ResetVector</B>
Synopsis: int <B>Blt_ResetVector</B> (<I>vecPtr</I>, <I>dataArr</I>, <I>numValues</I>,
<I>arraySize</I>, <I>freeProc</I>)
Blt_Vector *<I>vecPtr</I>; double *<I>dataArr</I>; int *<I>numValues</I>; int
*<I>arraySize</I>; Tcl_FreeProc *<I>freeProc</I>;
Description:
Resets the components of the vector pointed to by <I>vecPtr</I>.
Calling <B>Blt_ResetVector</B> will trigger the vector to dispatch
notifications to its clients. <I>DataArr</I> is the array of dou-
bles which represents the vector data. <I>NumValues</I> is the
number of elements in the array. <I>ArraySize</I> is the actual
size of the array (the array may be bigger than the number
of values stored in it). <I>FreeProc</I> indicates how the storage
for the vector component array (<I>dataArr</I>) was allocated. It
is used to determine how to reallocate memory when the vec-
tor is resized or destroyed. It must be TCL_DYNAMIC,
TCL_STATIC, TCL_VOLATILE, or a pointer to a function to
free the memory allocated for the vector array. If <I>freeProc</I>
is TCL_VOLATILE, it indicates that <I>dataArr</I> must be copied
and saved. If <I>freeProc</I> is TCL_DYNAMIC, it indicates that
<I>dataArr</I> was dynamically allocated and that Tcl should free
<I>dataArr</I> if necessary. Static indicates that nothing should
be done to release storage for <I>dataArr</I>.
Results: Returns TCL_OK if the vector is successfully resized. If
<I>newSize</I> is negative, a vector <I>vecName</I> does not exist, or
memory cannot be allocated for the vector, then TCL_ERROR
is returned and <I>interp->result</I> will contain an error mes-
sage.
<B>Blt_ResizeVector</B>
Synopsis: int <B>Blt_ResizeVector</B> (<I>vecPtr</I>, <I>newSize</I>)
Blt_Vector *<I>vecPtr</I>; int <I>newSize</I>;
Description:
Resets the length of the vector pointed to by <I>vecPtr</I> to
<I>newSize</I>. If <I>newSize</I> is smaller than the current size of
the vector, it is truncated. If <I>newSize</I> is greater, the
vector is extended and the new components are initialized
to 0.0. Calling <B>Blt_ResetVector</B> will trigger the vector to
dispatch notifications.
Results: Returns 1 if a vector <I>vecName</I> exists and 0 otherwise.
If your application needs to be notified when a vector changes, it
can allocate a unique <I>client</I> <I>identifier</I> for itself. Using this iden-
tifier, you can then register a call-back to be made whenever the
vector is updated or destroyed. By default, the call-backs are made
at the next idle point. This can be changed to occur at the time the
vector is modified. An application can allocate more than one iden-
tifier for any vector. When the client application is done with the
vector, it should free the identifier.
The call-back routine must of the following type.
typedef void (<B>Blt_VectorChangedProc</B>) (Tcl_Interp *<I>interp</I>,
ClientData <I>clientData</I>, Blt_VectorNotify <I>notify</I>);
<I>ClientData</I> is passed to this routine whenever it is called. You can
use this to pass information to the call-back. The <I>notify</I> argument
indicates whether the vector has been updated of destroyed. It is an
enumerated type.
typedef enum {
BLT_VECTOR_NOTIFY_UPDATE=1,
BLT_VECTOR_NOTIFY_DESTROY=2 } <B>Blt_VectorNotify</B>;
<B>Blt_AllocVectorId</B>
Synopsis: Blt_VectorId <B>Blt_AllocVectorId</B> (<I>interp</I>, <I>vecName</I>)
Tcl_Interp *<I>interp</I>; char *<I>vecName</I>;
Description:
Allocates an client identifier for with the vector <I>vec-</I>
<I>Name</I>. This identifier can be used to specify a call-
back which is triggered when the vector is updated or
destroyed.
Results: Returns a client identifier if successful. If <I>vecName</I>
is not the name of a vector, then NULL is returned and
<I>interp->result</I> will contain an error message.
<B>Blt_GetVectorById</B>
Synopsis: int <B>Blt_GetVector</B> (<I>interp</I>, <I>clientId</I>, <I>vecPtrPtr</I>)
Tcl_Interp *<I>interp</I>; Blt_VectorId <I>clientId</I>; Blt_Vector
**<I>vecPtrPtr</I>;
Description:
Retrieves the vector used by <I>clientId</I>. <I>ClientId</I> is a
valid vector client identifier allocated by
Specifies a call-back routine to be called whenever the
vector associated with <I>clientId</I> is updated or deleted.
<I>Proc</I> is a pointer to call-back routine and must be of
the type <B>Blt_VectorChangedProc</B>. <I>ClientData</I> is a one-
word value to be passed to the routine when it is
invoked. If <I>proc</I> is NULL, then the client is not noti-
fied.
Results: The designated call-back procedure will be invoked when
the vector is updated or destroyed.
<B>Blt_FreeVectorId</B>
Synopsis: void <B>Blt_FreeVectorId</B> (<I>clientId</I>);
Blt_VectorId <I>clientId</I>;
Description:
Frees the client identifier. Memory allocated for the
identifier is released. The client will no longer be
notified when the vector is modified.
Results: The designated call-back procedure will be no longer be
invoked when the vector is updated or destroyed.
<B>Blt_NameOfVectorId</B>
Synopsis: char *<B>Blt_NameOfVectorId</B> (<I>clientId</I>);
Blt_VectorId <I>clientId</I>;
Description:
Retrieves the name of the vector associated with the
client identifier <I>clientId</I>.
Results: Returns the name of the vector associated with <I>clientId</I>.
If <I>clientId</I> is not an identifier or the vector has been
destroyed, NULL is returned.
<B>Blt_InstallIndexProc</B>
Synopsis: void <B>Blt_InstallIndexProc</B> (<I>indexName</I>, <I>procPtr</I>)
char *<I>indexName</I>; Blt_VectorIndexProc *<I>procPtr</I>;
Description:
Registers a function to be called to retrieved the index
<I>indexName</I> from the vector's array variable.
typedef double Blt_VectorIndexProc(Vector *vecPtr);
The function will be passed a pointer to the vector.
reset shortly. The vector is updated when <B>lt_ResetVector</B> is called.
Blt_ResetVector makes the changes visible to the Tcl interface and
other vector clients (such as a graph widget).
#include <tcl.h> #include <blt.h> Blt_Vector *vecPtr; double
*newArr; FILE *f; struct stat statBuf; int numBytes, numValues;
f = fopen("binary.dat", "r"); fstat(fileno(f), &statBuf); numBytes =
(int)statBuf.st_size;
/* Allocate an array big enough to hold all the data */ newArr = (dou-
ble *)malloc(numBytes); numValues = numBytes / sizeof(double);
fread((void *)newArr, numValues, sizeof(double), f); fclose(f);
if (Blt_VectorExists(interp, "data")) {
if (Blt_GetVector(interp, "data", &vecPtr) != TCL_OK) {
return TCL_ERROR;
} } else {
if (Blt_CreateVector(interp, "data", 0, &vecPtr) != TCL_OK) {
return TCL_ERROR;
} } /*
* Reset the vector. Clients will be notified when Tk is idle.
* TCL_DYNAMIC tells the vector to free the memory allocated
* if it needs to reallocate or destroy the vector.
*/ if (Blt_ResetVector(vecPtr, newArr, numValues, numValues,
TCL_DYNAMIC) != TCL_OK) {
return TCL_ERROR; }
</PRE>
<H2>INCOMPATIBILITIES</H2><PRE>
In previous versions, if the array variable isn't global (i.e. local to
a Tcl procedure), the vector is automatically destroyed when the proce-
dure returns. proc doit {} {
# Temporary vector x
vector <B>x(10)</B>
set <B>x(9)</B> 2.0
... }
This has changed. Variables are not automatically destroyed when their
variable is unset. You can restore the old behavior by setting the
"-watchunset" switch.
</PRE>
<H2>KEYWORDS</H2><PRE>
vector, graph, widget
BLT BLT_VERSION blt::vector(n)
</PRE>
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