Table of Contents
stripchart - 2D strip chart for plotting x
and y coordinate data.
stripchart pathName ?option value ?...
The stripchart command creates a strip chart 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 strip chart.
The stripchart
is essentially the same as the graph widget. It works almost exactly
the very same way.
The use of a strip chart differs in that the X-axis
typically refers to time points. Data values are added at intervals. The
strip chart lets you automatically maintain a view of the most recent
time points. The axis options -shiftby and -autorange control this. You
can specify different line styles for data points (see the -styles option).
The stripchart command creates a new window for plotting
two-dimensional data (x,y coordinates). Data points are plotted in a box
displayed in the center of the new window. This is the plotting area .
The coordinate axes are displayed in the margins around the plotting
area. By default, the legend is displayed in the right margin. The title
is displayed in top margin.
A strip chart is composed of several components:
coordinate axes, data elements, legend, grid, cross hairs, pens, postscript,
and annotation markers.
- axis
- The stripchart widget can display up to
four coordinate axes (two X-coordinate and two Y-coordinate axes), but you
can create and use 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 of each major tick.
- crosshairs
- Cross hairs are used to finely
position the mouse pointer in relation to the coordinate axes. Two perpendicular
lines are drawn across the plotting area, intersecting at the current
location of the mouse pointer.
- 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 symbol, 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 widgets.
- pen
- Pens define attributes (both symbol and line style)
for elements. Data elements use pens to specify how they should be drawn.
A data element may use many pens at once. Here, the particular pen
used for a data point is determined from each element's weight vector
(see the element's -weight and -style options).
- postscript
- The widget
can generate encapsulated PostScript output. This component has several
options to configure how the PostScript is generated.
stripchart
pathName ?option value ?...
The stripchart command creates a new window
pathName and makes it into a stripchart widget. At the time this command
is invoked, there must not exist a window named pathName , but pathName
's parent must exist. Additional options may may be specified on the command
line or in the option database to configure aspects of the strip chart
such as its colors and font. See the configure operation below for the
exact details as to what option and value pairs are valid.
If successful,
stripchart returns the path name of the widget. It also creates a new
Tcl command by the same name. You can use this command to perform various
operations that query or modify the graph. The general form is:
pathName
operation ?arg ?...
Both operation and its arguments determine the exact
behavior of the command. The operations available for the strip chart
are described in the STRIPCHART OPERATIONS
section.
The command can
also be used to access components of the strip chart.
pathName component
operation ?arg ?...
The operation, now located after the name of the component,
is the function to be performed on that component. Each component has its
own set of operations that manipulate that component. They will be described
below in their own sections.
The stripchart command creates a
new strip chart.
# Create a new strip chart. Plotting area is black.
stripchart .s -plotbackground black
A new Tcl command .s is also created.
This command can be used to query and modify the strip chart. For example,
to change the title of the strip chart to "My Plot", you use the new command
and the widget's configure operation.
# Change the title.
.s configure
-title "My Plot"
A strip chart 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 element component.
# Create a new element
named "line1"
.s 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 and Y coordinates are specified using lists of
numbers. Alternately, BLT vectors could be used to hold the X-Y coordinates.
# Create two vectors and add them to the strip chart.
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 }
.s element create line1 -xdata
xVec -ydata yVec
The advantage of using vectors is that when you modify
one, the graph is automatically redrawn to display the new values.
#
Change the X-Y coordinates of the first point.
set xVec(0) 0.18
set yVec(0)
25.18
An element named line1 is now created in .s . By default, the element's
label in the legend will be also line1 . You can change the label, or specify
no legend entry, again using the element's configure operation.
# Don't
display "line1" in the legend.
.s element configure line1 -label ""
You
can configure more than just the element's label. An element has many attributes
such as symbol type and size, dashed or solid lines, colors, line width,
etc.
.s element configure line1 -symbol square -color red \
-dashes { 2 4
2 } -linewidth 2 -pixels 2c
Four coordinate axes are automatically created:
x , x2 , y , and y2 . And by default, elements are mapped onto the axes
x and y . This can be changed with the -mapx and -mapy options.
# Map
"line1" on the alternate Y-axis "y2".
.s element configure line1 -mapy y2
Axes can be configured in many ways too. For example, you change the
scale of the Y-axis from linear to log using the axis operation.
# Y-axis
is log scale.
.s axis configure y -logscale yes
Axis limits are reset by
simply specifying new axis limits using the -min and -max configuration
options.
.s axis configure x -min 1.0 -max 1.5
.s axis configure y -min 12.0
-max 55.15
By default, the limits of the axis are determined from data
values. To reset back to the default limits, set the -min and -max options
to the empty value.
# Reset the axes to autoscale again.
.s axis configure
x -min {} -max {}
.s axis configure y -min {} -max {}
It's common with strip
charts to automatically maintain a view of the most recent time points.
You can do this my setting the -autorange option.
.s axis configure
x -autorange 20.0
If the time points are added in X-coordinates 1.0 unit,
only the last twenty time points will be displayed. As more data is added,
the view will march along.
Sometimes the rate of data is so high that changing
the axis limits with each additional time point is prohibitive. You can
use the -shiftby option to define an increment to shift the view when
needed.
.s axis configure x -shiftby 15.0
When the view is shifted, it
will allow a range of 15 new time points to be added until the axis limits
are recomputed.
By default, the legend is displayed in the right margin.
You can change this or any other legend configuration options using the
legend component.
# Configure the legend font, color, and relief
.s
legend configure -position left -relief raised \
-font fixed -fg blue
To
prevent the legend from being displayed, turn on the -hide option.
#
Don't display the legend.
.s legend configure -hide yes
The stripchart
widget has simple drawing procedures called markers. They can be used
to highlight or annotate data in the strip chart. The types of markers
available are bitmaps, images, polygons, lines, or windows. Markers can
be used, for example, to mark or brush points. Here is a text marker
which labels the data first point. Markers are created using the marker
operation.
# Create a label for the first data point of "line1".
.s 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 -anchor , -xoffset , and -yoffset options are used to display
the marker above and to the left of the data point, so that the actual
data point isn't covered by the marker. By default, markers are drawn last,
on top of data. You can change this with the -under option.
# Draw the
label before elements are drawn.
.s marker configure first_marker -under
yes
You can add cross hairs or grid lines using the crosshairs and grid
operations.
# Display both cross hairs and grid lines.
.s crosshairs
configure -hide no -color red
.s grid configure -hide no -dashes { 2 2 }
Finally, to get hardcopy of the strip chart, use the postscript operation.
# Print the strip chart into file "file.ps"
.s postscript output file.ps
-maxpect yes -decorations no
This generates a file file.ps containing the
encapsulated PostScript of the strip chart. The option -maxpect says to
scale the plot to the size of the page. Turning off the -decorations option
indicates that no borders or color backgrounds should be displayed (i.e.
the background of the margins, legend, and plotting area will be white).
- pathName axis operation ?arg ?...
- See the AXIS
COMPONENTS
section.
- pathName bar elemName ?option value ?...
- Creates a
new barchart element elemName . It's an error if an element elemName already
exists. See the manual for barchart for details about what option and
value pairs are valid.
- pathName cget option
- Returns the current value
of the stripchart configuration option given by option . Option may be
any option described below for the configure operation.
- pathName configure
?option value ?...
- Queries or modifies the configuration options of the
strip chart. If option isn't specified, a list describing all of the current
options for pathName is returned. If option is specified, but not value
, then a list describing option is returned. If one or more option and
value pairs are specified, then for each pair, the stripchart option
option is set to value . The following options are valid for the stripchart.
- -background color
- Sets the background color. This includes the margins
and legend, but not the plotting area.
- -borderwidth pixels
- Sets the width
of the 3-D border around the outside edge of the widget. The -relief option
determines if the border is to be drawn. The default is 2 .
- -bottommargin
pixels
- Specifies the size of the margin below the X-coordinate axis.
If pixels is 0 , the size of the margin is selected automatically. The
default is 0 .
- -bufferelements boolean
- Indicates whether an internal pixmap
to buffer the display of data elements should be used. If boolean is
true, data elements are drawn to an internal pixmap. This option is especially
useful when the strip chart is redrawn frequently while the remains data
unchanged (for example, moving a marker across the plot). See the SPEED
TIPS
section. The default is 1 .
- -cursor cursor
- Specifies the widget's
cursor. The default cursor is crosshair .
- -font fontName
- Specifies the
title font. The default is *-Helvetica-Bold-R-Normal-*-18-180-* .
- -halo pixels
- Specifies a maximum distance to consider when searching for the closest
data point (see the element's closest operation below). Data points further
than pixels away are ignored. The default is 0.5i .
- -height pixels
- Specifies
the requested height of widget. The default is 4i .
- -invertxy boolean
- Indicates whether the placement X-axis and Y-axis should be inverted. If
boolean is true, the X and Y axes are swapped. The default is 0 .
- -justify
justify
- Specifies how the title should be justified. This matters only
when the title contains more than one line of text. Justify must be left
, right , or center . The default is center .
- -leftmargin pixels
- Sets
the size of the margin from the left edge of the window to the Y-coordinate
axis. If pixels is 0 , the size is calculated automatically. The default
is 0 .
- -plotbackground color
- Specifies the background color of the plotting
area. The default is white .
- -plotborderwidth pixels
- Sets the width of
the 3-D border around the plotting area. The -plotrelief option determines
if a border is drawn. The default is 2 .
- -plotpadx pad
- Sets the amount
of padding to be added to the left and right sides of the plotting area.
Pad can be a list of one or two screen distances. If pad 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 pad is just one distance, both the
left and right sides are padded evenly. The default is 8 .
- -plotpady pad
- Sets the amount of padding to be added to the top and bottom of the
plotting area. Pad can be a list of one or two screen distances. If pad
has two elements, the top of the plotting area is padded by the first
distance and the bottom by the second. If pad is just one distance, both
the top and bottom are padded evenly. The default is 8 .
- -plotrelief relief
- Specifies the 3-D effect for the plotting area. Relief indicates how
the interior of the plotting area should appear relative to rest of the
strip chart; for example, raised means the plot should appear to protrude
from the strip chart, relative to the surface of the strip chart. The
default is sunken .
- -relief relief
- Specifies the 3-D effect for the widget.
Relief indicates how the strip chart should appear relative to widget
it is packed into; for example, raised means the strip chart should appear
to protrude. The default is flat .
- -rightmargin pixels
- Sets the size of
margin from the plotting area to the right edge of the window. By default,
the legend is displayed in this margin. If pixels is than 1, the margin
size is selected automatically.
- -takefocus focus
- Provides information
used when moving the focus from window to window via keyboard traversal
(e.g., Tab and Shift-Tab). If focus is 0 , this means that this window should
be skipped entirely during keyboard traversal. 1 means that the this
window should always receive the input focus. An empty value means that
the traversal scripts make the decision whether to focus on the window.
The default is "" .
- -tile image
- Specifies a tiled background. If image
isn't "" , the background is tiled using image . Otherwise, the normal
background color is drawn (see the -background option). Image must be
an image created using the Tk image command. The default is "" .
- -title
text
- Sets the title to text . If text is "" , no title will be displayed.
- -topmargin pixels
- Specifies the size of the margin above the x2 axis.
If pixels is 0 , the margin size is calculated automatically.
- -width pixels
- Specifies the requested width of the widget. The default is 5i .
- pathName
crosshairs operation ?arg ?
- See the CROSSHAIRS COMPONENT
section.
- pathName element operation ?arg ?...
- See the ELEMENT COMPONENTS
section.
- pathName extents item
- Returns the size of a particular item in the
strip chart. Item must be either leftmargin , rightmargin , topmargin
, bottommargin , plotwidth , or plotheight .
- pathName grid operation ?arg
?...
- See the GRID COMPONENT
section.
- pathName invtransform winX winY
- 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 graph coordinates.
- pathName legend operation
?arg ?...
- See the LEGEND COMPONENT
section.
- pathName line elemName ?option
value ?...
- The operation is the same as element .
- pathName marker operation
?arg ?...
- See the MARKER COMPONENTS
section.
- pathName postscript operation
?arg ?...
- See the POSTSCRIPT COMPONENT
section.
- pathName snap photoName
- Takes a snapshot of the strip chart and stores the contents in the photo
image photoName . PhotoName is the name of a Tk photo image that must
already exist.
- pathName transform x y
- 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.
- pathName
xaxis operation ?arg ?...
- pathName x2axis operation ?arg ?...
- pathName
yaxis operation ?arg ?...
- pathName y2axis operation ?arg ?...
- See the
AXIS COMPONENTS
section.
A strip chart is composed
of several components: coordinate axes, data elements, legend, grid, cross
hairs, postscript, and annotation markers. Instead of one big set of configuration
options and operations, the strip chart is partitioned, where each component
has its own configuration options and operations that specifically control
that aspect or part of the strip chart.
Four coordinate
axes are automatically created: two X-coordinate axes (x and x2 ) and
two Y-coordinate axes (y , and y2 ). By default, the axis x is located
in the bottom margin, y in the left margin, x2 in the top margin, and
y2 in the right margin.
An axis consists of the axis line, title, major
and minor ticks, and tick labels. Major ticks are drawn at uniform intervals
along the axis. Each tick is labeled with its coordinate value. Minor
ticks are drawn at uniform intervals within major ticks.
The range of
the axis controls what region of data is plotted. Data points outside the
minimum and maximum limits of the axis are not plotted. By default, the
minimum and maximum limits are determined from the data, but you can reset
either limit.
You can create and use several axes. To create an axis, invoke
the axis component and its create operation.
# Create a new axis called
"temperature"
.s axis create temperature
You map data elements to an
axis using the element's -mapy and -mapx configuration options. They specify
the coordinate axes an element is mapped onto.
# Now map the temperature
data to this axis.
.s element create "temp" -xdata $x -ydata $tempData \
-mapy temperature
While you can have many axes, only four axes can
be displayed simultaneously. They are drawn in each of the margins surrounding
the plotting area. The axes x and y are drawn in the bottom and left margins.
The axes x2 and y2 are drawn in top and right margins. Only x and y are
shown by default. Note that the axes can have different scales.
To display
a different axis, you invoke one of the following components: xaxis ,
yaxis , x2axis , and y2axis . The use operation designates the axis to
be drawn in the corresponding margin: xaxis in the bottom, yaxis in
the left, x2axis in the top, and y2axis in the right.
# Display the
axis temperature in the left margin.
.s yaxis use temperature
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 as 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.
- pathName axis cget axisName
option
- Returns the current value of the option given by option for
axisName . Option may be any option described below for the axis configure
operation.
- pathName axis configure axisName ?option value ?...
- Queries
or modifies the configuration options of axisName . If option isn't specified,
a list describing all the current options for axisName is returned. If
option is specified, but not value , then a list describing option is
returned. If one or more option and value pairs are specified, then
for each pair, the axis option option is set to value . The following
options are valid for axes.
- -autorange range
- Sets the range of values
for the axis to range . The axis limits are automatically reset to display
the most recent data points in this range. If range is 0.0, the range
is determined from the limits of the data. If -min or -max are specified,
they override this option. The default is 0.0 .
- -color color
- Sets the color
of the axis and tick labels. The default is black .
- -command prefix
- Specifies
a Tcl command to be invoked when formatting the axis tick labels. Prefix
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
prefix to "" . The default is "" .
Please note that this procedure is
invoked while the strip chart is redrawn. You may query the configuration
options. But do not reset them, because this can have unexpected results.
- -descending boolean
- Indicates whether the values along the axis are
monotonically increasing or decreasing. If boolean is true, the axis
values will be decreasing. The default is 0 .
- -hide boolean
- Indicates
whether the axis is displayed.
- -justify justify
- Specifies how the axis
title should be justified. This matters only when the axis title contains
more than one line of text. Justify must be left , right , or center .
The default is center .
- -limits formatStr
- 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. FormatStr
is a list of one or two format descriptions. If one description is supplied,
both the minimum and maximum limits are formatted in the same way. If
two, the first designates the format for the minimum limit, the second
for the maximum. If "" is given as either description, then the that
limit will not be displayed. The default is "" .
- -linewidth pixels
- Sets
the width of the axis and tick lines. The default is 1 pixel.
- -logscale
boolean
- Indicates whether the scale of the axis is logarithmic or linear.
If boolean is true, the axis is logarithmic. The default scale is linear.
- -loose boolean
- Indicates whether the limits of the axis should fit the
data points tightly, at the outermost data points, or loosely, at the
outer tick intervals. This is relevant only when the axis limit is automatically
calculated. If boolean is true, the axis range is "loose". The default
is 0 .
- -majorticks majorList
- Specifies where to display major axis ticks.
You can use this option to display ticks at non-uniform intervals. MajorList
is a list of axis coordinates designating the location of major ticks.
No minor ticks are drawn. If majorList is "" , major ticks will be
automatically computed. The default is "" .
- -max value
- Sets the maximum
limit of axisName . Any data point greater than value is not displayed.
If value is "" , the maximum limit is calculated using the largest
data value. The default is "" .
- -min value
- Sets the minimum limit of axisName
. Any data point less than value is not displayed. If value is "" ,
the minimum limit is calculated using the smallest data value. The default
is "" .
- -minorticks minorList
- Specifies where to display minor axis ticks.
You can use this option to display minor ticks at non-uniform intervals.
MinorList 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 -majortick
option is also set. If minorList is "" , minor ticks will be automatically
computed. The default is "" .
- -rotate theta
- Specifies the how many degrees
to rotate the axis tick labels. Theta is a real value representing the
number of degrees to rotate the tick labels. The default is 0.0 degrees.
- -shiftby value
- Specifies how much to automatically shift the range of
the axis. When the new data exceeds the current axis maximum, the maximum
is increased in increments of value . You can use this option to prevent
the axis limits from being recomputed at each new time point. If value
is 0.0, then no automatic shifting is done. The default is 0.0 .
- -showticks
boolean
- Indicates whether axis ticks should be drawn. If boolean is
true, ticks are drawn. If false, only the axis line is drawn. The default
is 1 .
- -stepsize value
- Specifies the interval between major axis ticks.
If value isn't a valid interval (must be less than the axis range),
the request is ignored and the step size is automatically calculated.
- -subdivisions
number
- Indicates how many minor axis ticks are to be drawn. For example,
if number is two, only one minor tick is drawn. If number is one, no
minor ticks are displayed. The default is 2 .
- -tickfont fontName
- Specifies
the font for axis tick labels. The default is *-Courier-Bold-R-Normal-*-100-*
.
- -ticklength pixels
- Sets the length of major and minor ticks (minor ticks
are half the length of major ticks). If pixels is less than zero, the
axis will be inverted with ticks drawn pointing towards the plot. The
default is 0.1i .
- -title text
- Sets the title of the axis. If text is ""
, no axis title will be displayed.
- -titlecolor color
- Sets the color
of the axis title. The default is black .
- -titlefont fontName
- Specifies
the font for axis title. The default is *-Helvetica-Bold-R-Normal-*-14-140-* .
Axis
configuration options may be also be set by the option command. The resource
class is Axis . The resource names are the names of the axes (such as
x or x2 ).
option add *Stripchart.Axis.Color blue
option add *Stripchart.x.LogScale
true
option add *Stripchart.x2.LogScale false
- pathName axis create axisName
?option value ?...
- Creates a new axis by the name axisName . No axis by
the same name can already exist. Option and value are described in above
in the axis configure operation.
- pathName axis delete ?axisName ?...
- Deletes
the named axes. An axis is not really deleted until it is not longer in
use, so it's safe to delete axes mapped to elements.
- pathName axis invtransform
axisName value
- Performs the inverse transformation, changing the screen
coordinate value to a graph coordinate, mapping the value mapped to axisName
. Returns the graph coordinate.
- pathName axis limits axisName
- Returns
a list of the minimum and maximum limits for axisName . The order of the
list is min max .
- pathName axis names ?pattern ?...
- Returns a list of axes
matching zero or more patterns. If no pattern argument is give, the names
of all axes are returned.
- pathName axis transform axisName value
- Transforms
the coordinate value to a screen coordinate by mapping the it to axisName
. Returns the transformed screen coordinate.
Only four axes can be displayed
simultaneously. By default, they are x , y , x2 , and y2 . You can swap
in a different axis with use operation of the special axis components:
xaxis , x2axis , yaxis , and y2axis .
.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 xaxis , x2axis , yaxis , and y2axis
components operate on an axis location rather than a specific axis like
the more general axis component does. The xaxis component manages the
X-axis located in the bottom margin (whatever axis that happens to be).
Likewise, yaxis uses the Y-axis in the left margin, x2axis the top X-axis,
and y2axis the right Y-axis.
They implicitly control the axis that is currently
using to that location. By default, xaxis uses the x axis, yaxis uses
y , x2axis uses x2 , and y2axis uses y2 . These components can be more
convenient to use than always determining what axes are current being
displayed by the graph.
The following operations are available for axes.
They mirror exactly the operations of the axis component. The axis argument
must be xaxis , x2axis , yaxis , or y2axis .
- pathName axis cget option
- pathName axis configure ?option value ?...
- pathName axis invtransform
value
- pathName axis limits
- pathName axis transform value
- pathName
axis use ?axisName ?
- Designates the axis axisName is to be displayed
at this location. AxisName can not be already in use at another location.
This command returns the name of the axis currently using this location.
Cross hairs consist of two intersecting lines (one
vertical and one horizontal) drawn completely across the plotting area.
They are used to position the mouse in relation to the coordinate axes.
Cross hairs differ from line markers in that they are implemented using
XOR drawing primitives. This means that they can be quickly drawn and erased
without redrawing the entire strip chart.
The following operations are
available for cross hairs:
- pathName crosshairs cget option
- Returns the
current value of the cross hairs configuration option given by option
. Option may be any option described below for the cross hairs configure
operation.
- pathName crosshairs configure ?option value ?...
- Queries or
modifies the configuration options of the cross hairs. If option isn't
specified, a list describing all the current options for the cross hairs
is returned. If option is specified, but not value , then a list describing
option is returned. If one or more option and value pairs are specified,
then for each pair, the cross hairs option option is set to value . The
following options are available for cross hairs.
- -color color
- Sets the
color of the cross hairs. The default is black .
- -dashes dashList
- Sets
the dash style of the cross hairs. DashList 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 dashList is ""
, the cross hairs will be solid lines.
- -hide boolean
- Indicates whether
cross hairs are drawn. If boolean is true, cross hairs are not drawn.
The default is yes .
- -linewidth pixels
- Set the width of the cross hair
lines. The default is 1 .
- -position pos
- Specifies the screen position
where the cross hairs intersect. Pos must be in the form "@x,y ", where
x and y are the window coordinates of the intersection.
Cross hairs configuration
options may be also be set by the option command. The resource name and
class are crosshairs and Crosshairs respectively.
option add *Stripchart.Crosshairs.LineWidth
2
option add *Stripchart.Crosshairs.Color red
- pathName crosshairs
off
- Turns of the cross hairs.
- pathName crosshairs on
- Turns on the
display of the cross hairs.
- pathName crosshairs toggle
- Toggles the current
state of the cross hairs, alternately mapping and unmapping the cross
hairs.
A data element represents a set of data. It
contains x and y vectors containing the coordinates of the data points.
Elements can be displayed with a symbol at each data point and lines
connecting the points. Elements also control the appearance of the data,
such as the symbol type, line width, color etc.
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.
- pathName element
activate elemName ?index ?...
- Specifies the data points of element elemName
to be drawn using active foreground and background colors. ElemName
is the name of the element and index is a number representing the index
of the data point. If no indices are present then all data points become
active.
- pathName element cget elemName option
- Returns the current value
of the element configuration option given by option . Option may be
any option described below for the element configure operation.
- pathName
element closest x y varName ?option value ?... ?elemName ?...
- Finds the data
point closest to the window coordinates x and y in the element elemName
. ElemName is the name of an element, that must not be hidden. If no
elements are specified, then all visible elements are searched. It returns
via the array variable varName the name of the closest element, the index
of its closest point, and the graph coordinates of the point. Returns 0
, if no data point within the threshold distance can be found, otherwise
1 is returned. The following option -value pairs are available.
- -halo
pixels
- Specifies a threshold distance where selected data points are
ignored. Pixels 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 stripchart's
-halo option.
- -interpolate boolean
- Indicates that both the data points
and interpolated points along the line segment formed should be considered.
If boolean is true, the closest line segment will be selected instead
of the closest point. If this option isn't specified, boolean defaults
to 0 .
- pathName element configure elemName ?option value ?...
- Queries
or modifies the configuration options for elements. If option isn't specified,
a list describing all the current options for elemName is returned. If
option is specified, but not value , then a list describing the option
option is returned. If one or more option and value pairs are specified,
then for each pair, the element option option is set to value . The following
options are valid for elements.
- -activepen penName
- Specifies pen to use
to draw active element. If penName is "" , no active elements will be
drawn. The default is activeLine .
- -color color
- Sets the color of the
traces connecting the data points.
- -dashes dashList
- Sets the dash style
of element line. DashList 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 dashList is "" , the lines will
be solid.
- -data coordList
- Specifies the X-Y coordinates of the data. CoordList
is a list of numeric expressions representing the X-Y coordinate pairs
of each data point.
- -fill color
- Sets the interior color of symbols. If
color is "" , then the interior of the symbol is transparent. If color
is defcolor , then the color will be the same as the -color option. The
default is defcolor .
- -hide boolean
- Indicates whether the element is displayed.
The default is no .
- -label text
- Sets the element's label in the legend.
If text is "" , the element will have no entry in the legend. The default
label is the element's name.
- -linewidth pixels
- Sets the width of the connecting
lines between data points. If pixels is 0 , no connecting lines will
be drawn between symbols. The default is 0 .
- -mapx xAxis
- Selects the X-axis
to map the element's X-coordinates onto. XAxis must be the name of an axis.
The default is x .
- -mapy yAxis
- Selects the Y-axis to map the element's
Y-coordinates onto. YAxis must be the name of an axis. The default is y
.
- -offdash color
- Sets the color of the stripes when traces are dashed
(see the -dashes option). If color is "" , then the "off" pixels will
represent gaps instead of stripes. If color is defcolor , then the color
will be the same as the -color option. The default is defcolor .
- -outline
color
- Sets the color or the outline around each symbol. If color is
"" , then no outline is drawn. If color is defcolor , then the color will
be the same as the -color option. The default is defcolor .
- -outlinewidth
pixels
- Sets the width of the outline bordering each symbol. If pixels
is 0 , no outline will be drawn. The default is 1 .
- -pixels pixels
- Sets
the size of symbols. If pixels is 0 , no symbols will be drawn. The default
is 0.125i .
- -scalesymbols boolean
- If boolean is true, the size of the
symbols drawn for elemName 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 -pixels 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 boolean is false, the element's symbols are drawn
at the designated size, regardless of axis scales. The default is 0 .
- -smooth
smooth
- Specifies how connecting line segments are drawn between data
points. Smooth can be either linear , step , natural , or quadratic .
If smooth is linear , a single line segment is drawn, connecting both
data points. When smooth is step , two line segments are drawn. The first
is a horizontal line segment which steps the next x-coordinate. The second
is a vertical line, moving to the next y-coordinate. Both natural and
quadratic generate multiple segments between data points. If natural
, the segments are generated using a cubic spline. If quadratic , a quadratic
spline is used. The default is linear .
- -styles styleList
- Specifies what
pen to use based upon the range of weights given. StyleList 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 -weight option) falls in this range, are drawn with
this pen. If no range is specified it defaults to the number of the pen
in the list.
- -symbol symbol
- Specifies the symbol for data points. Symbol
can be either square , circle , diamond , plus , cross , splus , scross
, triangle , "" (where no symbol is drawn), or a bitmap. Bitmaps are
specified as "source ?mask ?", where source is the name of the bitmap,
and mask is the bitmap's optional mask. The default is circle .
- -weights
wVec
- Specifies the weights of the individual data points. This, in
conjunction with the list pen styles (see the -styles option) controls
how data points are drawn. WVec is the name of a BLT vector or a list
of numeric expressions representing the weights for each data point.
- -xdata
xVec
- Specifies the x-coordinates of the data. XVec is the name of a
BLT vector or a list of numeric expressions.
- -ydata yVec
- Specifies the
y-coordinates of the data. YVec is the name of a BLT vector or a list
of numeric expressions.
Element configuration options may also be set by
the option command. The resource class is Element . The resource name
is the name of the element.
option add *Stripchart.Element.symbol line
option add *Stripchart.e1.symbol line
- pathName element create elemName
?option value ?...
- Creates a new element elemName . It's an error is an
element elemName already exists. If additional arguments are present,
they specify options valid for element configure operation.
- pathName
element deactivate elemName ?elemName ?...
- Deactivates all the elements
matching pattern . Elements whose names match any of the patterns given
are redrawn using their normal colors.
- pathName element delete ?elemName
?...
- Deletes all the named elements. The graph is automatically redrawn.
- pathName element exists elemName
- Returns 1 if an element elemName
currently exists and 0 otherwise.
- pathName element names ?pattern ?...
- Returns the elements matching one or more pattern. If no pattern is
given, the names of all elements is returned.
- pathName element show ?nameList
?
- Queries or modifies the element display list. The element display
list designates the elements drawn and in what order. NameList is a list
of elements to be displayed in the order they are named. If there is no
nameList argument, the current display list is returned.
- pathName element
type elemName
- Returns the type of elemName . If the element is a bar
element, the commands returns the string "bar" , otherwise it returns
"line" .
Grid lines extend from the major and minor ticks
of each axis horizontally or vertically across the plotting area. The
following operations are available for grid lines.
- pathName grid cget option
- Returns the current value of the grid line configuration option given
by option . Option may be any option described below for the grid configure
operation.
- pathName grid configure ?option value ?...
- Queries or modifies
the configuration options for grid lines. If option isn't specified, a
list describing all the current grid options for pathName is returned.
If option is specified, but not value , then a list describing option
is returned. If one or more option and value pairs are specified, then
for each pair, the grid line option option is set to value . The following
options are valid for grid lines.
- -color color
- Sets the color of the
grid lines. The default is black .
- -dashes dashList
- Sets the dash style
of the grid lines. DashList 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 dashList is "" , the grid will be solid
lines.
- -hide boolean
- Indicates whether the grid should be drawn. If boolean
is true, grid lines are not shown. The default is yes .
- -linewidth pixels
- Sets the width of grid lines. The default width is 1 .
- -mapx xAxis
- Specifies
the X-axis to display grid lines. XAxis must be the name of an axis. The
default is x .
- -mapy yAxis
- Specifies the Y-axis to display grid lines.
YAxis must be the name of an axis. The default is y .
- -minor boolean
- Indicates
whether the grid lines should be drawn for minor ticks. If boolean is
true, the lines will appear at minor tick intervals. The default is 1
.
Grid configuration options may also be set by the option command. The
resource name and class are grid and Grid respectively.
option add
*Stripchart.grid.LineWidth 2
option add *Stripchart.Grid.Color black
- pathName grid off
- Turns off the display the grid lines.
- pathName grid
on
- Turns on the display the grid lines.
- pathName grid toggle
- Toggles
the display of the grid.
The legend displays a list
of the data elements. Each entry consists of the element's symbol and label.
The legend can appear in any margin (the default location is in the right
margin). It can also be positioned anywhere within the plotting area.
The
following operations are valid for the legend.
- pathName legend activate
pattern ...
- Selects legend entries to be drawn using the active legend colors
and relief. All entries whose element names match pattern are selected.
To be selected, the element name must match only one pattern .
- pathName
legend cget option
- Returns the current value of a legend configuration
option. Option may be any option described below in the legend configure
operation.
- pathName legend configure ?option value ?...
- Queries or modifies
the configuration options for the legend. If option isn't specified, a
list describing the current legend options for pathName is returned.
If option is specified, but not value , then a list describing option
is returned. If one or more option and value pairs are specified, then
for each pair, the legend option option is set to value . The following
options are valid for the legend.
- -activebackground color
- Sets the background
color for active legend entries. All legend entries marked active (see
the legend activate operation) are drawn using this background color.
- -activeborderwidth pixels
- Sets the width of the 3-D border around the
outside edge of the active legend entries. The default is 2 .
- -activeforeground
color
- Sets the foreground color for active legend entries. All legend
entries marked as active (see the legend activate operation) are drawn
using this foreground color.
- -activerelief relief
- Specifies the 3-D effect
desired for active legend entries. Relief 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 legend, relative to the surface
of the legend. The default is flat .
- -anchor anchor
- Tells how to position
the legend relative to the positioning point for the legend. This is dependent
on the value of the -position option. The default is center .
- left or
right
- The anchor describes how to position the legend vertically.
- top
or bottom
- The anchor describes how to position the legend horizontally.
- @x,y
- The anchor specifies how to position the legend relative to the
positioning point. For example, if anchor is center then the legend is
centered on the point; if anchor is n then the legend will be drawn
such that the top center point of the rectangular region occupied by the
legend will be at the positioning point.
- plotarea
- The anchor specifies
how to position the legend relative to the plotting area. For example,
if anchor is center then the legend is centered in the plotting area;
if anchor is ne then the legend will be drawn such that occupies the
upper right corner of the plotting area.
- -background color
- Sets the background
color of the legend. If color is "" , the legend background with be transparent.
- -borderwidth pixels
- Sets the width of the 3-D border around the outside
edge of the legend (if such border is being drawn; the relief option
determines this). The default is 2 pixels.
- -font fontName
- FontName specifies
a font to use when drawing the labels of each element into the legend.
The default is *-Helvetica-Bold-R-Normal-*-12-120-* .
- -foreground color
- Sets
the foreground color of the text drawn for the element's label. The default
is black .
- -hide boolean
- Indicates whether the legend should be displayed.
If boolean is true, the legend will not be draw. The default is no .
- -ipadx
pad
- Sets the amount of internal padding to be added to the width of
each legend entry. Pad can be a list of one or two screen distances.
If pad has two elements, the left side of the legend entry is padded
by the first distance and the right side by the second. If pad is just
one distance, both the left and right sides are padded evenly. The default
is 2 .
- -ipady pad
- Sets an amount of internal padding to be added to the
height of each legend entry. Pad can be a list of one or two screen distances.
If pad has two elements, the top of the entry is padded by the first
distance and the bottom by the second. If pad is just one distance, both
the top and bottom of the entry are padded evenly. The default is 2 .
- -padx
pad
- Sets the padding to the left and right exteriors of the legend. Pad
can be a list of one or two screen distances. If pad has two elements,
the left side of the legend is padded by the first distance and the right
side by the second. If pad has just one distance, both the left and right
sides are padded evenly. The default is 4 .
- -pady pad
- Sets the padding
above and below the legend. Pad can be a list of one or two screen distances.
If pad has two elements, the area above the legend is padded by the
first distance and the area below by the second. If pad is just one distance,
both the top and bottom areas are padded evenly. The default is 0 .
- -position
pos
- Specifies where the legend is drawn. The -anchor option also affects
where the legend is positioned. If pos is left , left , top , or bottom
, the legend is drawn in the specified margin. If pos is plotarea , then
the legend is drawn inside the plotting area at a particular anchor. If
pos is in the form "@x,y ", where x and y are the window coordinates,
the legend is drawn in the plotting area at the specified coordinates.
The default is right .
- -raised boolean
- Indicates whether the legend is
above or below the data elements. This matters only if the legend is in
the plotting area. If boolean is true, the legend will be drawn on top
of any elements that may overlap it. The default is no .
- -relief relief
- Specifies the 3-D effect for the border around the legend. Relief specifies
how the interior of the legend should appear relative to the strip chart;
for example, raised means the legend should appear to protrude from the
strip chart, relative to the surface of the strip chart. The default is
sunken .
Legend configuration options may also be set by the option command.
The resource name and class are legend and Legend respectively.
option
add *Stripchart.legend.Foreground blue
option add *Stripchart.Legend.Relief
raised
- pathName legend deactivate pattern ...
- Selects legend entries
to be drawn using the normal legend colors and relief. All entries whose
element names match pattern are selected. To be selected, the element
name must match only one pattern .
- pathName legend get pos
- Returns the
name of the element whose entry is at the screen position pos in the
legend. Pos must be in the form "@x,y ", where x and y are window coordinates.
If the given coordinates do not lie over a legend entry, "" is returned.
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 -weight and -style 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.
.s pen configure "activeLine"
-color green
You can create and use any number of pens. To create a pen,
invoke the pen component and its create operation.
.s pen create myPen
You map pens to a data element using either the element's -pen or -activepen
options.
.s 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 -styles option).
.s 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 element's default attributes.
The following operations are available for pen components.
- pathName pen
cget penName option
- Returns the current value of the option given by
option for penName . Option may be any option described below for the
pen configure operation.
- pathName pen configure penName ?option value
?...
- Queries or modifies the configuration options of penName . If option
isn't specified, a list describing the current options for penName is
returned. If option is specified, but not value , then a list describing
option is returned. If one or more option and value pairs are specified,
then for each pair, the pen option option is set to value . The following
options are valid for pens.
- -color color
- Sets the color of the traces
connecting the data points.
- -dashes dashList
- Sets the dash style of
element line. DashList 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 dashList is "" , the lines will
be solid.
- -fill color
- Sets the interior color of symbols. If color is
"" , then the interior of the symbol is transparent. If color is defcolor
, then the color will be the same as the -color option. The default is
defcolor .
- -linewidth pixels
- Sets the width of the connecting lines between
data points. If pixels is 0 , no connecting lines will be drawn between
symbols. The default is 0 .
- -offdash color
- Sets the color of the stripes
when traces are dashed (see the -dashes option). If color is "" , then
the "off" pixels will represent gaps instead of stripes. If color is
defcolor , then the color will be the same as the -color option. The default
is defcolor .
- -outline color
- Sets the color or the outline around each
symbol. If color is "" , then no outline is drawn. If color is defcolor
, then the color will be the same as the -color option. The default is
defcolor .
- -outlinewidth pixels
- Sets the width of the outline bordering
each symbol. If pixels is 0 , no outline will be drawn. The default is
1 .
- -pixels pixels
- Sets the size of symbols. If pixels is 0 , no symbols
will be drawn. The default is 0.125i .
- -symbol symbol
- Specifies the symbol
for data points. Symbol can be either square , circle , diamond , plus
, cross , splus , scross , triangle , "" (where no symbol is drawn),
or a bitmap. Bitmaps are specified as "source ?mask ?", where source
is the name of the bitmap, and mask is the bitmap's optional mask. The
default is circle .
- -type elemType
- Specifies the type of element the
pen is to be used with. This option should only be employed when creating
the pen. This is for those that wish to mix different types of elements
(bars and lines) on the same graph. The default type is "line".
Pen configuration
options may be also be set by the option command. The resource class
is Pen . The resource names are the names of the pens.
option add *Stripchart.Pen.Color
blue
option add *Stripchart.activeLine.color green
- pathName pen create
penName ?option value ?...
- Creates a new pen by the name penName . No pen
by the same name can already exist. Option and value are described in
above in the pen configure operation.
- pathName pen delete ?penName ?...
- Deletes the named pens. A pen is not really deleted until it is not longer
in use, so it's safe to delete pens mapped to elements.
- pathName pen names
?pattern ?...
- Returns a list of pens matching zero or more patterns. If
no pattern argument is give, the names of all pens are returned.
The strip chart can generate encapsulated PostScript output.
There are several configuration options you can specify to control how
the plot is 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.
- pathName
postscript cget option
- Returns the current value of the postscript
option given by option . Option may be any option described below for
the postscript configure operation.
- pathName postscript configure ?option
value ?...
- Queries or modifies the configuration options for PostScript
generation. If option isn't specified, a list describing the current
postscript options for pathName is returned. If option is specified,
but not value , then a list describing option is returned. If one or
more option and value pairs are specified, then for each pair, the postscript
option option is set to value . The following postscript options are
available.
- -center boolean
- Indicates whether the plot should be centered
on the PostScript page. If boolean is false, the plot will be placed
in the upper left corner of the page. The default is 1 .
- -colormap varName
- VarName must be the name of a global array variable that specifies
a color mapping from the X color name to PostScript. Each element of varName
must consist of PostScript code to set a particular color value (e.g. ``1.0
1.0 0.0 setrgbcolor ''). When outputting color information in PostScript,
the array variable varName is checked to see if an element of the name
of the color exists. If so, it uses the value of the element as the PostScript
command to set the color. If this option hasn't been specified, or if there
isn't an entry in varName for a given color, then it uses the red, green,
and blue intensities from the X color.
- -colormode mode
- Specifies how to
output color information. Mode must be either color (for full color
output), gray (convert all colors to their gray-scale equivalents) or
mono (convert foreground colors to black and background colors to white).
The default mode is color .
- -fontmap varName
- VarName must be the name
of a global array variable that specifies a font mapping from the X font
name to PostScript. Each element of varName must consist of a Tcl list
with one or two elements, which are the name and point size of a PostScript
font. When outputting PostScript commands for a particular font, the array
variable varName is checked to see an element of the specified font
exists. If there is such an element, then the font information contained
in that element is used in the PostScript output. (If the point size is
omitted from the list, the point size of the X font is used). Otherwise
the X font is examined in an attempt to guess what PostScript font to
use. This works only for fonts whose foundry property is Adobe (such
as Times, Helvetica, Courier, etc.). If all of this fails then the font
defaults to Helvetica-Bold .
- -decorations boolean
- Indicates if PostScript
commands to generate color backgrounds and 3-D borders should be output.
If boolean is false, the background will be white and no 3-D borders
will be generated. The default is 1 .
- -height pixels
- Sets the height of
the plot. This lets you plot the stripchart with a height different from
the one displayed on the screen. If pixels is 0, the height is the same
as the displayed height. The default is 0 .
- -landscape boolean
- If boolean
is true, this specifies the printed area is to be rotated 90 degrees.
In non-rotated output the X-axis of the printed area runs along the short
dimension of the page (``portrait'' orientation); in rotated output the X-axis
runs along the long dimension of the page (``landscape'' orientation). Defaults
to 0 .
- -maxpect boolean
- Indicates to scale the the plot so that it fills
the PostScript page. The aspect ratio of the strip chart is still retained.
The default is 0 .
- -padx pad
- Sets the horizontal padding for the left
and right page borders. The borders are exterior to the plot. Pad can
be a list of one or two screen distances. If pad has two elements, the
left border is padded by the first distance and the right border by the
second. If pad has just one distance, both the left and right borders
are padded evenly. The default is 1i .
- -pady pad
- Sets the vertical padding
for the top and bottom page borders. The borders are exterior to the plot.
Pad can be a list of one or two screen distances. If pad has two elements,
the top border is padded by the first distance and the bottom border by
the second. If pad has just one distance, both the top and bottom borders
are padded evenly. The default is 1i .
- -paperheight pixels
- Sets the height
of the postscript page. This can be used to select between different page
sizes (letter, A4, etc). The default height is 11.0i .
- -paperwidth pixels
- Sets the width of the postscript page. This can be used to select between
different page sizes (letter, A4, etc). The default width is 8.5i .
- -width
pixels
- Sets the width of the plot. This lets you plot the strip chart
with a width different from the one drawn on the screen. If pixels 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 option command. The resource
name and class are postscript and Postscript respectively.
option add
*Stripchart.postscript.Decorations false
option add *Stripchart.Postscript.Landscape
true
- pathName postscript output ?fileName ? ?option value ?...
- Outputs
a file of encapsulated PostScript. If a fileName argument isn't present,
the command returns the PostScript. If any option-value pairs are present,
they set configuration options controlling how the PostScript is generated.
Option and value can be anything accepted by the postscript configure
operation above.
Markers are simple drawing procedures
used to annotate or highlight areas of the strip chart. 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 -under option.
Markers, in contrast to elements,
don't affect the scaling of the coordinate axes. They can also have elastic
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.
- pathName marker after markerId ?afterId ?
- Changes
the order of the markers, drawing the first marker after the second. If
no second afterId 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.
- pathName marker before markerId ?beforeId ?
- Changes the order of the
markers, drawing the first marker before the second. If no second beforeId
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.
- pathName marker cget
option
- Returns the current value of the marker configuration option
given by option . Option may be any option described below in the configure
operation.
- pathName marker configure markerId ?option value ?...
- Queries
or modifies the configuration options for markers. If option isn't specified,
a list describing the current options for markerId is returned. If option
is specified, but not value , then a list describing option is returned.
If one or more option and value pairs are specified, then for each pair,
the marker option option is set to value .
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.
- -coords coordList
- Specifies the coordinates of the marker. CoordList 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 coordList is "" ,
the marker will not be displayed. The default is "" .
- -element elemName
- Links the marker with the element elemName . The marker is drawn only
if the element is also currently displayed (see the element's show operation).
If elemName is "" , the marker is always drawn. The default is "" .
- -hide
boolean
- Indicates whether the marker is drawn. If boolean is true,
the marker is not drawn. The default is no .
- -mapx xAxis
- Specifies the
X-axis to map the marker's X-coordinates onto. XAxis must the name of an
axis. The default is x .
- -mapy yAxis
- Specifies the Y-axis to map the marker's
Y-coordinates onto. YAxis must the name of an axis. The default is y .
- -name
markerId
- Changes the identifier for the marker. The identifier markerId
can not already be used by another marker. If this option isn't specified,
the marker's name is uniquely generated.
- -under boolean
- Indicates whether
the marker is drawn below/above data elements. If boolean is true, the
marker is be drawn underneath the data element symbols and lines. Otherwise,
the marker is drawn on top of the element. The default is 0 .
- -xoffset pixels
- Specifies a screen distance to offset the marker horizontally. Pixels
is a valid screen distance, such as 2 or 1.2i . The default is 0 .
- -yoffset
pixels
- Specifies a screen distance to offset the markers vertically.
Pixels is a valid screen distance, such as 2 or 1.2i . The default is
0 .
Marker configuration options may also be set by the option command.
The resource class is either BitmapMarker , ImageMarker , LineMarker
, PolygonMarker , TextMarker , or WindowMarker , depending on the type
of marker. The resource name is the name of the marker.
option add *Stripchart.TextMarker.Foreground
white
option add *Stripchart.BitmapMarker.Foreground white
option add
*Stripchart.m1.Background blue
- pathName marker create type ?option
value ?...
- Creates a marker of the selected type. Type may be either text
, line , bitmap , image , polygon , or window . This command returns the
marker identifier, used as the markerId argument in the other marker-related
commands. If the -name option is used, this overrides the normal marker
identifier. If the name provided is already used for another marker, the
new marker will replace the old.
- pathName marker delete ?name ?...
- Removes
one of more markers. The graph will automatically be redrawn without the
marker. .
- pathName marker exists markerId
- Returns 1 if the marker
markerId exists and 0 otherwise.
- pathName marker names ?pattern ?
- Returns the names of all the markers that currently exist. If pattern
is supplied, only those markers whose names match it will be returned.
- pathName marker type markerId
- Returns the type of the marker given
by markerId , such as line or text . If markerId is not a valid a marker
identifier, "" is returned.
A bitmap marker displays a
bitmap. The size of the bitmap is controlled by the number of coordinates
specified. If two coordinates, they specify the position of the top-left
corner of the bitmap. The bitmap retains its normal width and height.
If four coordinates, the first and second pairs of coordinates represent
the corners of the bitmap. The bitmap will be stretched or reduced as
necessary to fit into the bounding rectangle.
Bitmap markers are created
with the marker's create operation in the form:
pathName marker create
bitmap ?option value ?...
There may be many option -value pairs, each
sets a configuration options for the marker. These same option -value
pairs may be used with the marker's configure operation.
The following
options are specific to bitmap markers:
- -background color
- Sets the background
color of the bitmap. If color is "" , the background color will be transparent.
The default background color is white .
- -bitmap bitmap
- Specifies the
bitmap to be displayed. If bitmap is "" , the marker will not be displayed.
The default is "" .
- -foreground color
- Sets the foreground color of the
bitmap. The default foreground color is black .
- -mask mask
- Specifies a
mask for the bitmap to be displayed. This mask is a bitmap itself, denoting
the pixels that are transparent. If mask is "" , all pixels of the bitmap
will be drawn. The default is "" .
- -rotate theta
- Sets the rotation of
the bitmap. Theta is a real number representing the angle of rotation
in degrees. The marker is first rotated and then placed according to its
anchor position. The default rotation is 0.0 .
A image marker
displays an image. Image markers are created with the marker's create
operation in the form:
pathName marker create image ?option value ?...
There may be many option -value pairs, each sets a configuration option
for the marker. These same option -value pairs may be used with the marker's
configure operation.
The following options are specific to image markers:
- -anchor anchor
- Anchor tells how to position the image relative to the
positioning point for the image. For example, if anchor is center then
the image is centered on the point; if anchor is n then the image will
be drawn such that the top center point of the rectangular region occupied
by the image will be at the positioning point. This option defaults to
center .
- -image image
- Specifies the image to be drawn. If image is ""
, the marker will not be drawn. The default is "" .
A line
marker displays one or more connected line segments. Line markers are created
with marker's create operation in the form:
pathName marker create line
?option value ?...
There may be many option -value pairs, each sets a configuration
option for the marker. These same option -value pairs may be used with
the marker's configure operation.
The following options are specific to
line markers:
- -background color
- Sets the background color of the line.
The option is affects the line color only when the -stipple option is
set. If this option isn't specified then it defaults to white .
- -dashes
dashList
- Sets the dash style of the line. DashList is a list of up to
11 numbers that alternately represent the lengths of the dashes and gaps
on the line. Each number must be between 1 and 255. If dashList is ""
, the marker line will be solid.
- -foreground color
- Sets the foreground
color. The default foreground color is black .
- -linewidth pixels
- Sets
the width of the lines. The default width is 0 .
- -stipple bitmap
- Specifies
a stipple pattern used to draw the line, rather than a solid line. Bitmap
specifies a bitmap to use as the stipple pattern. If bitmap is "" ,
then the line is drawn in a solid fashion. The default is "" .
A polygon marker displays a closed region described as two or
more connected line segments. It is assumed the first and last points
are connected. Polygon markers are created using the marker create operation
in the form:
pathName marker create polygon ?option value ?...
There
may be many option -value pairs, each sets a configuration option for
the marker. These same option -value pairs may be used with the marker
configure command to change the marker's configuration. The following options
are supported for polygon markers:
- -dashes dashList
- Sets the dash style
of the outline of the polygon. DashList 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 dashList is "" , the outline
will be a solid line.
- -fill color
- Sets the fill color of the polygon.
If color is "" , then the interior of the polygon is transparent. The
default is white .
- -linewidth pixels
- Sets the width of the outline of
the polygon. If pixels is zero, no outline is drawn. The default is 0
.
- -outline color
- Sets the color of the outline of the polygon. If the
polygon is stippled (see the -stipple option), then this represents the
foreground color of the stipple. The default is black .
- -stipple bitmap
- Specifies that the polygon should be drawn with a stippled pattern rather
than a solid color. Bitmap specifies a bitmap to use as the stipple pattern.
If bitmap is "" , then the polygon is filled with a solid color (if
the -fill option is set). The default is "" .
A text marker
displays a string of characters on one or more lines of text. Embedded
newlines cause line breaks. They may be used to annotate regions of the
strip chart. Text markers are created with the create operation in the
form:
pathName marker create text ?option value ?...
There may be many
option -value pairs, each sets a configuration option for the text marker.
These same option -value pairs may be used with the marker's configure
operation.
The following options are specific to text markers:
- -anchor
anchor
- Anchor tells how to position the text relative to the positioning
point for the text. For example, if anchor is center then the text is
centered on the point; if anchor 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 .
- -background color
- Sets the background color of the text string. If color is "" , the
background will be transparent. The default is white .
- -font fontName
- Specifies the font of the text. The default is *-Helvetica-Bold-R-Normal-*-120-*
.
- -foreground color
- Sets the foreground color of the text. The default
is black .
- -justify justify
- Specifies how the text should be justified.
This matters only when the marker contains more than one line of text.
Justify must be left , right , or center . The default is center .
- -padx
pad
- Sets the padding to the left and right exteriors of the text. Pad
can be a list of one or two screen distances. If pad has two elements,
the left side of the text is padded by the first distance and the right
side by the second. If pad has just one distance, both the left and right
sides are padded evenly. The default is 4 .
- -pady pad
- Sets the padding
above and below the text. Pad can be a list of one or two screen distances.
If pad has two elements, the area above the text is padded by the first
distance and the area below by the second. If pad is just one distance,
both the top and bottom areas are padded evenly. The default is 4 .
- -rotate
theta
- Specifies the number of degrees to rotate the text. Theta is
a real number representing the angle of rotation. The marker is first
rotated along its center and is then drawn according to its anchor position.
The default is 0.0 .
- -text text
- Specifies the text of the marker. The exact
way the text is displayed may be affected by other options such as -anchor
or -rotate .
A window marker displays a widget at a given
position. Window markers are created with the marker's create operation
in the form:
pathName marker create window ?option value ?...
There may
be many option -value pairs, each sets a configuration option for the
marker. These same option -value pairs may be used with the marker's configure
command.
The following options are specific to window markers:
- -anchor
anchor
- Anchor tells how to position the widget relative to the positioning
point for the widget. For example, if anchor is center then the widget
is centered on the point; if anchor 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
.
- -height pixels
- 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.
- -width pixels
- 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.
- -window pathName
- Specifies
the widget to be managed. PathName must be a child of the stripchart
widget.
Specific stripchart 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 Enter , Leave , ButtonPress
, Motion , and KeyPress ).
Only one element or marker can be picked during
an event. This means, that if the mouse is directly over both an element
and a marker, only the uppermost component is selected. This isn't true
for legend entries. Both a legend entry and an element (or marker) binding
commands will be invoked if both items are picked.
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 -bindtags option). When this occurs,
all of the matching bindings are invoked. A binding associated with the
element name is invoked first, followed by one binding for each of the
element's bindtags. If there are multiple matching bindings for a single
tag, then only the most specific binding is invoked. A continue command
in a binding script terminates that script, and a break command terminates
that script and skips any remaining scripts for the event, just as for
the bind command.
The -bindtagsR option for these components controls addition
tag names which can be matched. Implicitly elements and markers always
have tags matching their names. Setting the value of the -bindtags option
doesn't change this.
You can manipulate data elements from
the C language. There may be situations where it is too expensive to translate
the data values from ASCII strings. Or you might want to read data in
a special file format.
Data can manipulated from the C language using BLT
vectors. You specify the x and y data coordinates of an element as vectors
and manipulate the vector from C. The strip chart will be redrawn automatically
after the vectors are updated.
From Tcl, create the vectors and configure
the element to use them.
vector X Y
.s element configure line1 -xdata
X -ydata Y
To set data points from C, you pass the values as arrays of
doubles using the Blt_ResetVector call. The vector is reset with the
new data and at the next idle point (when Tk re-enters its event loop),
the strip chart 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", 50, &xVec) != TCL_OK) ||
(Blt_GetVector(interp,
"Y", 50, &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 vector manual page for more details.
There may be cases where the strip chart 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.
·- Try to minimize the number of
data points. The more data points the looked at, the more work the strip
chart must do.
·- If your data is generated as floating point values, the
time required to convert the data values to and from ASCII strings can
be significant, especially when there any many data points. You can avoid
the redundant string-to-decimal conversions using the C API to BLT vectors.
·- Data elements without symbols are drawn faster than with symbols. Set the
data element's -symbol option to none . If you need to draw symbols, try
using the simple symbols such as splus and scross .
·- Don't stipple or dash
the element. Solid lines are much faster.
·- If you update data elements frequently,
try turning off the widget's -bufferelements option. When the strip chart
is first displayed, it draws data elements into an internal pixmap. The
pixmap acts as a cache, so that when the strip chart needs to be redrawn
again, and the data elements or coordinate axes haven't changed, the pixmap
is simply copied to the screen. This is especially useful when you are
using markers to highlight points and regions on the strip chart. But
if the strip chart is updated frequently, changing either the element
data or coordinate axes, the buffering becomes redundant.
Auto-scale routines do not use requested min/max limits as boundaries when
the axis is logarithmically scaled.
The PostScript output generated for
polygons with more than 1500 points may exceed the limits of some printers
(See PostScript Language Reference Manual, page 568). The work-around is
to break the polygon into separate pieces.
The
-mapped options are obsoleted and will be removed. You can achieve the
same results using the -hide option instead.
# Works for now.
.s legend
configure -mapped no
# Instead use this.
.s legend configure -hide yes
stripchart, graph, widget
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