.. _graph:
Graph
-----
.. class:: Graph
Syntax:
``g = new Graph()``
``g = new Graph(0)``
Description:
An instance of the Graph class manages a window on which x-y plots can
be drawn by calling various member functions.
The first form immediately maps the window to the screen. With a 0 argument
the window is not mapped but can be sized and placed with the :func:`view` function.
Example:
The most basic interpreter prototype for producing a plot follows:
.. code-block::
none
objref g //Creates an object reference "g" which can be made to
//point to any object.
g = new Graph() //Assigns "g" the role of pointing to a Graph instance
//created from the Graph class, and produces
//a graph window with x and y axes on the
//screen.
g.size(0, 10, -1, 1) // specify coordinate system for the canvas drawing area
// numbers refer to xmin, xmax, ymin, ymax respectively
g.beginline() //The next g.line command will move the drawing pen
// to the indicated point without drawing anything
for(x=0; x<=10; x=x+0.1){ //States that x values to be plotted
//will go from 0 to 10 in increments
//of 0.1.
g.line(x, sin(x)) //States that the y values on the plot
//will be the sin of the x values.
}
g.flush() //Actually draws the plot on the graph in the window.
The function ``.line()``, however, only allows the user to plot one function
per ``for`` loop, whereas the function ``.plot()`` can produce several
plots per ``for`` loop and is therefore more effective in comparing plots.
You must use ``.begin()`` and ``.addvar()`` or ``.addexpr()`` in
conjunction with the ``.plot`` function.
.. code-block::
none
objref g
g = new Graph()
g.size(0, 10, -1, 1)
g.addexpr("sin(x)") //stores sin(x) as a function to be plotted in g
g.addexpr("cos(x)") //stores cos(x) for use with g
g.addexpr("exp(-x)") //stores exp(x) for use with g
x=0
g.begin() //The next g.plot command will move the drawing pens
// for the three curves to indicated x position
for(x=0; x<=10; x=x+0.1){
g.plot(x) // The x value used for each expression in the
// addexpr list
}
g.flush()
The size in the above example is appropriate to show the sine waves nicely
but the view of the exponential only shows the first few points before it
goes out of view. Hold the right mouse button while the mouse in in the
graph window and select the "View = plot" menu item to see the entire exponential.
Selecting the "Whole Scene" menu item will return to the size specified
in the size command.
----
.. method:: Graph.xaxis
Syntax:
``g.xaxis()``
``g.xaxis(mode)``
``g.xaxis(xstart, xstop)``
``g.xaxis(xstart, xstop, ypos, ntic, nminor, invert, shownumbers)``
Description:
The single mode argument draws both x and y axes (no arg == mode 0).
See :func:`yaxis` for a complete description of the arguments.
----
.. method:: Graph.yaxis
Syntax:
``g.yaxis()``
``g.yaxis(mode)``
``g.yaxis(ystart, ystop)``
``g.yaxis(ystart, ystop, ypos, ntic, nminor, invert, shownumbers)``
Description:
The single mode argument draws both x and y axes (no arg == mode 0).
mode = 0
view axes (axes in each view drawn dynamically)
when graph is created these axes are the default
mode = 1
fixed axes as in long form but start and stop chosen
according to first view size.
mode = 2
view box (box axes drawn dynamically)
mode = 3
erase axes
Arguments which specify the numbers on the axis are rounded,
and the number of tic marks is chosen so that axis labels are short numbers
(eg. not 3.3333333... or the like).
The *xpos* argument gives the location of the yaxis on the xaxis (default 0).
Without the *ntic* argument (or *ntic*\ =-1),
the number of tics will be chosen for you.
*nminor* is the number
of minor tic marks.
*shownumbers*\ =0 will not draw the axis labels.
*invert*\ =1 will invert the axes.
Note:
It is easiest to control the size of the axes and the scale of
the graph through the graphical user interface. Normally, when a
new graph is declared (eg. ``g = new Graph()``), the y axis
ranges from 20-180 and the x axis ranges from 50-250.
With the mouse arrow on the graph window, click on the right button
and set the arrow on :guilabel:`View` at the top of the button window
column. A second button
window will appear to the right of the first, and from this button window
you can select several options. Two of the most common are:
1) view=plot
Size the window to best-fit the plot which it contains.
2) Zoom in/out
Allows you to click on the left mouse button and perform the following
tasks:
move arrow to the right
scale down the x axis (eg. 50 - 250 becomes 100 - 110)
"shift" + move arrow to the right
view parts of the axis which are to the left of the original window
move arrow to the left
scale up the x axis (eg. 50 - 250 becomes -100 - 500)
"shift" + move arrow to the left
view parts of the axis which are to the right of the original window
move arrow up
scale down the y axis (eg. 20 - 180 becomes 57.5 - 62)
"shift" + move arrow up
view parts of the axis which are below the original window
move arrow down
scale up the y axis (eg. 20 - 180 becomes -10,000 - 5,000)
"shift" + move arrow down
view parts of the axis which are above the original window
You can also use the size command to determine the size of what you view in the
graph window. Eg. ``g.size(-1,1,-1,1)`` makes both axes go from -1 to 1.
----
.. method:: Graph.addvar
Syntax:
``g.addvar("variable")``
``g.addvar("variable", color_index, brush_index)``
``g.addvar("label", "variable")``
``g.addvar("label", "variable", color_index, brush_index)``
``g.addvar("label", &variable, ...)``
Description:
Add the variable to the list of items graphed when ``g.plot(x)`` is called.
The address of the variable is computed so this is fast. The current
color and brush is used if the optional arguments are not present. The name
of the variable is
also added to the graph as a label associated with the line. If the
first two args are strings, then the first "label" arg is associated
with the line on the
graph whereas the second arg defines the variable.
The second arg may be an explicit pointer arg which allows g.addvar to be
used in Python using section(x)._ref_rangevar .
.. note::
To automatically plot a variable added to a graph ``g`` with addvar against
``t`` during a ``run()``, ``stdrun.hoc`` must be loaded and the graph must be
added to a graphList, such as by executing ``graphList[0].append(g)``.
----
.. method:: Graph.addexpr
Syntax:
``g.addexpr("expression")``
``g.addexpr("expression", color_index, brush_index)``
``g.addexpr("label", "expr", object, ....)``
Description:
Add an expression (eg. sin(x), cos(x), exp(x)) to the list of items graphed when
``g.plot(x)`` is called.
The current
color and brush is used if the optional arguments are not present. A label
is also added to the graph that indicates the name of the variable.
The expression is interpreted every time ``g.plot(x)`` is
called so it is more general than :func:`addvar`, but slower.
If the optional label is present that string will appear as the label instead
of the expr string. If the optional object is present the expr will be
evaluated in the context of that object.
Example:
.. code-block::
none
objref g //Creates an object reference "g" which will
//point to the graph object.
g = new Graph() //Assigns "g" the role of pointing to a Graph
g.size(0,10,-1,1) //created from the Graph class, and produces
//a graph window with x and y axes on the
//screen.
g.addexpr("sin(x)") //stores sin(x) as a function to be plotted in g graphs
g.addexpr("cos(x)") //stores cos(x) for use with g
g.addexpr("exp(-x)") //stores exp(x) for use with g
x=0 // has to be defined prior to execution of expressions
g.begin() //Tells the interpreter that commands to plot
//specific functions will follow.
for(x=0; x<=10; x=x+0.1){ //States that x values to be plotted
//will go from 0 to 10 in increments
//of 0.1.
g.plot(x) //States that the y values on the plot
//will be the sin of the x values.
}
g.flush() //Actually draws the plot on the graph in the window.
----
.. method:: Graph.addobject
Syntax:
``g.addobject(rangevarplot)``
``g.addobject(rangevarplot, color, brush)``
Description:
Adds the :class:`RangeVarPlot` to the list of items to be plotted on
:meth:`Graph.flush`
----
.. method:: Graph.begin
Syntax:
``g.begin()``
Description:
Initialize the list of graph variables so the next ``g.plot(x)``
is the first point of each graph line.
Example:
.. code-block::
none
objref g //Creates an object reference "g" which will
//point to the graph object.
g = new Graph() //Assigns "g" the role of pointing to a Graph
//created from the Graph class, and produces
//a graph window with x and y axes on the
//screen.
g.addexpr("sin(x)") //stores sin(x) as a function to be plotted in g graphs
g.addexpr("cos(x)") //stores cos(x) for use with g
g.addexpr("-exp(x)") //stores exp(x) for use with g
x=0
g.begin() //Tells the interpreter that commands to plot
//specific functions will follow.
for(x=0; x<=10; x=x+0.1){ //States that x values to be plotted
//will go from 0 to 10 in increments
//of 0.1.
g.plot(x) //States that the y values on the plot
//will be the sin of the x values.
}
g.flush() //Actually draws the plot on the graph in the window.
----
.. method:: Graph.plot
Syntax:
``g.plot(x)``
Description:
The abscissa value for each item in the list of graph lines. Usually
used in a ``for`` loop.
Example:
.. code-block::
none
objref g //Creates an object reference "g" which will
//point to the graph object.
g = new Graph() //Assigns "g" the role of pointing to a Graph
//created from the Graph class, and produces
//a graph window with x and y axes on the
//screen.
g.addexpr("sin(x)") //stores sin(x) as a function to be plotted in g graphs
g.addexpr("cos(x)") //stores cos(x) for use with g
g.addexpr("cos(2*x)") //stores cos(2*x) for use with g
x=0
g.begin() //Tells the interpreter that commands to plot
//specific functions will follow.
for(x=0; x<=10; x=x+0.1){ //States that x values to be plotted
//will go from 0 to 10 in increments
//of 0.1.
g.plot(x) //States that the y values on the plot
//will be the sin of the x values.
}
g.flush() //Actually draws the plot on the graph in the window.
----
.. method:: Graph.xexpr
Syntax:
``g.xexpr("expression")``
``g.xexpr("expression", usepointer)``
Description:
Use this expression for plotting two-dimensional functions such as (x(*t*), y(*t*)),
where the x and y coordinates are separately dependent on a single variable *t*.
This expression calculates the x value each time ``.plot`` is called, while functions
declared by ``.addexpr`` will calculate the y value when ``.plot`` is called.
This can be used for phase plane plots, etc. Note that the normal argument to
``.plot`` is ignored when such an expression is invoked. When ``usepointer``
is 1 the expression must be a variable name and its address is used.
Example:
.. code-block::
none
objref g //Creates an object reference "g" which will
//point to the graph object.
g = new Graph() //Assigns "g" the role of pointing to a Graph
//created from the Graph class, and produces
//a graph window with x and y axes on the
//screen.
g.size(-4,4,-4,4) //sizes the window to fit the graph
t = 0 //Declares t as a possible variable
g.addexpr("3*sin(t)") //stores 3*sin(t) as a function to be plotted in g graphs
g.color(3) //the next graph will be drawn in blue
g.addexpr("3*sin(2*t)") //stores 3*sin(2*t) as a function to be plotted
g.xexpr("3*cos(t)") //stores 3*cos(t) as the x function to be plotted in g graphs
//sin(x) becomes the y function
g.begin() //Tells the interpreter that commands to plot
//specific functions will follow.
for(t=0; t<=2*PI+0.1; t=t+0.1){ //States that x values to be plotted
//will go from 0 to 10 in increments
//of 0.1.
g.plot(t) //States that the y values on the plot
//will be the sin of the x values.
}
g.flush() //Actually draws the plot on the graph in the window.
plots a black circle of radius=3 and a blue infinity-like figure, spanning from x=-3
to x=3.
----
.. method:: Graph.flush
Syntax:
``.flush()``
Description:
Actually draw what has been placed in the graph scene. (If
you are continuing to compute you will also need to call :func:`doEvents`
before you see the results on the screen.) This redraws all objects
in the scene and therefore should not be executed very much during
plotting of lines with thousands of points.
.. warning::
Because Microsoft Windows is a second-class operating system, too many points, too close
together will not appear at all on a graph window. You can, in such a case, zoom in to view
selected parts of the function.
----
.. method:: Graph.fastflush
Syntax:
``.fastflush()``
Description:
Flushes only the :func:`plot` (x) points since the last :func:`flush`
(or ``fastflush``).
This is useful for seeing the progress of :func:`addvar` plots during long
computations in which the graphlines contain many thousands of points.
Make sure you do a normal ``.flush`` when the lines are complete since
fastflush does not notify the system of the true size of the lines.
In such cases, zooming, translation, and crosshairs do not always
work properly till after the ``flush()`` command has been given.
(Note, this is most useful for time plots).
.. code-block::
none
objectvar g
g = new Graph()
g.size(0,4000, -1,1)
g.addexpr("cos(x/100)")
g.addexpr("cos(x/150)")
g.addexpr("cos(x/200)")
g.addexpr("cos(x/250)")
g.addexpr("cos(x/300)")
g.addexpr("cos(x/450)")
proc pl() {
g.erase()
g.begin()
for (x=0; x < 4000; x=x+1) {
g.plot(x)
if (x%10 == 0) {
g.fastflush()
doNotify()
}
}
g.flush()
doNotify()
}
pl()
----
.. method:: Graph.family
Syntax:
``g.family(boolean)``
``g.family("varname")``
Description:
The first form is similar to the Keep Lines item in the graph menu of the
graphical user interface.
1
equivalent to the sequence ---Erase lines; Keep Lines toggled on;
use current graph color and brush when plotting the lines.
0
Turn off family mode. Original color restored to plot expressions;
Keep Lines toggled off.
With a string argument which is a variable name,
the string is printed as a label and when keep lines
is selected each line is labeled with the value of the variable.
When graphs are printed to a file in :ref:`printtofile_ascii` mode,
the lines are labeled
with these labels. If every line has a label and each line has the same size,
then the file is printed in matrix form.
----
.. method:: Graph.vector
Syntax:
``.vector(n, &x[0], &y[0])``
``.vector("namey")``
Description:
``.vector(n, &x[0], &y[0])``
Rudimentary graphing of a y-vector vs. a fixed x-vector. The y-vector
is reread on each ``.flush()`` (x-vector is not reread). Cannot save
and cannot keep lines.
Notes:
These vectors are assumed to be doubles and not vectors from
the Vector class. The Vector class has its own functions
:meth:`Vector.plot`, :meth:`Vector.line`, :meth:`Vector.mark`
for graphing vectors constructed in that class.
A segmentation violation will result if
n is greater than the vector size.
``.vector("namey")``
equivalent to ``.vector(n, ..., &namey[0])`` above with the advantage
that it is saved in a session (because the symbol name is known).
It is simpler in that the size n is obtained from the symbol but
the plot is vs. the index of the vector. Not implemented.
----
.. method:: Graph.getline
Syntax:
``thisindex = g.getline(previndex, xvec, yvec)``
Description:
Copy a graph line into the :class:`Vector`\ 's xvec and yvec. Those vectors are
resized to the number of points in the line. Also, if the line has a
label, it is copied to the vector as well (see :meth:`Vector.label`).
The index of the line is returned. To re-get the line at a later time
(assuming no line has been inserted into the graphlist earlier than
its index value --- new lines are generally appended to the list but
if an earlier line has been removed, the indices of all later lines will
be reduced) then use index-1 as the argument. Note that an argument of
-1 will always return the first line in the Graph. If the argument is
the index of the last line then -1 is returned and xvec and yvec are
unchanged. Note that thisindex is not necessarily equal to previndex+1.
Example:
To iterate over all the lines in a Graph use:
.. code-block::
none
objref xvec, yvec
xvec = new Vector()
yvec = new Vector()
for (j=0 i=-1; (i = Graph[0].getline(i, xvec, yvec) != -1 ; j+=1 ) {
// xvec and yvec contain the line with Graph internal index i.
// and can be associated with the sequential index j.
print j, i, yvec.label
xline[j] = xvec.c
yline[j] = yvec.cl // clone label as well
}
----
.. method:: Graph.line_info
Syntax:
``thisindex = g.line_info(previndex, Vector(5))``
Description:
For the next line after the internal index, previndex, copy the label into the
vector as well as colorindex, brushindex, label x location, label y location,
and label style and return the index of the line. If the argument is the
index of the last line then -1 is returned and Vector is unchanged.
Note that an argument of -1 will always return the line info for the first
polyline in the graph.
----
.. method:: Graph.erase
Syntax:
``.erase()``
Description:
Erase only the drawings of graph lines.
----
.. method:: Graph.erase_all
Syntax:
``e.erase_all()``
Description:
Erase everything on the graph.
----
.. method:: Graph.size
Syntax:
``g.size(xstart, xstop, ystart, ystop)``
``g.size(1-4)``
``g.size(&dbl[0])``
Description:
.size(*xstart*, *xstop*, *ystart*, *ystop*)
The natural size of the scene in model coordinates. The "Whole Scene"
menu item in the graphical user interface will change the view to this size.
Default axes are this size.
.size(1-4)
Returns left, right, bottom or top of first view of the scene. Useful for programming.
.size(&dbl[0])
Returns the xmin, xmax, ymin, ymax values of all marks and lines of more than two
points in the graph in dbl[0],..., dbl[3] respectively. This allows
convenient computation of a view size which will display everything on the
graph. See :ref:`gui_view_equal_plot`. In the absence of any graphics, it gives
the size as in the .size(1-4) prototype.
----
.. method:: Graph.label
Syntax:
``.label(x, y, "label")``
``.label(x, y)``
``.label("label")``
``.label(x, y, "string", fixtype, scale, x_align, y_align, color)``
Description:
``.label(x, y, "label")``
Draw a label at indicated position with current color.
``.label("label")``
Add a label one line below the previous label
``.label(x, y)``
Next ``label("string")`` will be printed at this location
The many arg form is used by sessions to completely specify an individual
label.
----
.. method:: Graph.fixed
Syntax:
``.fixed(scale)``
Description:
Sizes labels. Future labels are by default
attached with respect to scene coordinates. The labels maintain
their size as the view changes.
----
.. method:: Graph.vfixed
Syntax:
``.vfixed(scale)``
Description:
Sizes labels. Future labels are by default
attached with respect to relative view coordinates in which
(0,0) is the left,bottom and (1,1) is the right,top of the view.
Thus zooming and translation does not affect the placement of
the label.
----
.. method:: Graph.relative
Syntax:
``.relative(scale)``
Description:
I never used it so I don't know if it works. The most
useful labels are fixed in that they maintain their size as the
view is zoomed.
----
.. method:: Graph.align
Syntax:
``.align([x_align], [y_align])``
Description:
Alignment is a number between 0 and 1 which signifies which location
of the label is at the x,y position. .5 means centering. 0 means
left(bottom) alignment, 1 means right(top) alignment
Example:
.. code-block::
none
objref g
g = new Graph()
g.align(0, 0)
g.label(.5,.5, "left bottom at (.5,.5)")
g.align(0, 1)
g.label(.5,.5, "left top at (.5,.5)")
g.align(1, 0)
g.label(.5,.5, "right bottom at (.5,.5)")
g.align(.5,2)
g.label(.5,.5, "middle but twice height at (.5, .5)")
----
.. method:: Graph.color
Syntax:
``.color(index)``
``.color(index, "colorname")``
Description:
Set the default color (starts at 1 == black). The default color palette
is:
.. code-block::
none
0 white
1 black
2 red
3 blue
4 green
5 orange
6 brown
7 violet
8 yellow
9 gray
``.color(index, "colorname")``
Install a color in the Color Palette to be accessed with that index.
The possible indices are 0-100.
The user may also use the colors/brushes button in the graphical user interface, which
is called by placing the mouse arrow in the graph window and pressing the right button.
----
.. method:: Graph.brush
Syntax:
``.brush(index)``
``.brush(index, pattern, width)``
Description:
``.brush(index)``
Set the default brush. 0 is the thinnest line possible, 1-4 are
thickness in pixel. Higher indices cycle through these line
thicknesses with different brush patterns.
``.brush(index, pattern, width)``
Install a brush in the Brush Palette to be accessed with the index.
The width is in pixel coords (< 1000). The pattern is a 31 bit pattern
of 1's and 0's which is used to make dash patterns. Fractional widths
work with postscript but not idraw. Axes are drawn with the
nrn.defaults property ``*default_brush: 0.0``
The user may also use the :ref:`gui_changecolor_brush` button in the graphical user interface, which
is called by placing the mouse arrow in the graph window and pressing the right button.
----
.. method:: Graph.view
Syntax:
``.view(mleft, mbottom, mwidth, mheight, wleft,``
``wtop, wwidth, wheight)``
``.view(2)``
Description:
Map a view of the Shape scene. *m* stands for model coordinates
within the window,
*w* stands for screen coordinates for placement and size of the
window. The placement of the window with respect to the screen
is intended to be precise and is with respect to pixel coordinates
where 0,0 is the top left corner of the screen.
The single argument form maps a view in which the aspect ratio
between x and y axes is always 1. eg like a shape window.
----
.. method:: Graph.save_name
Syntax:
``.save_name("objectvar")``
``.save_name("objectvar", 1)``
Description:
The objectvar used to save the scene when the print window
manager is used to save a session.
If the second arg is present then info about the graph
is immediately saved to the open session file. This is used by objects
that create their own graphs but need to save graph information.
----
.. method:: Graph.beginline
Syntax:
``.beginline()``
``.beginline(color_index, brush_index)``
``.beginline("label")``
``.beginline("label", color, brush)``
Description:
State that the next ``g.line(x)``
is the first point of the next line to be graphed.
This is a less general command than ``.begin()`` which prepares a graph for
the ``.plot()`` command.
The optional label argument labels the line.
Example:
Notice that the argument to ``g.line()`` is the expression sin(x)
itself, whereas if you were using the ``.plot()`` command, the arguments
would have to be specified before the ``for`` loop using ``.addexpr()``
commands. The addexpr/begin/plot method of plotting is preferred since it
is capable of simultaneously plotting multiple lines.
.. code-block::
none
objref g //Creates an object reference "g" which will
//point to the graph object.
g = new Graph() //Assigns "g" the role of pointing to a Graph
//created from the Graph class, and produces
//a graph window with x and y axes on the
//screen.
g.beginline() //Tells the interpreter that commands to create a line for
//specific functions will follow.
for(x=0; x<=10; x=x+0.1){ //States that x values to be plotted
//will go from 0 to 10 in increments
//of 0.1.
g.line(x, sin(x)) //States that the y values on the line
//will be the sin of the x values.
}
g.flush() //Actually draws the plot on the graph in the window.
----
.. method:: Graph.line
Syntax:
``.line(x, y)``
Description:
Draw a line from the previous point to this point. This command is normally
used inside of a ``for`` loop. It is analogous to ``.plot()`` and the commands which
go along with it. In the case of ``.line()`` however, all arguments are given in
the line command itself. Therefore, the line command only plots one line at a time, whereas
the ``.plot*()`` command can plot several lines using the same for loop on the same graph.
This command takes arguments for both x and y values, so it can serve the same purpose of
the ``.plot`` command in conjunction with an ``.addexpr()`` command and an ``.xexpr()``
command.
Example:
.. code-block::
none
objref g
g = new Graph()
g.beginline()
for(t=0; t<=2*PI+0.1; t=t+0.1){
g.line(sin(t), cos(t))
}
g.flush()
graphs a circle of radius=1, just as would the following code using ``g.plot()``:
.. code-block::
none
objref g
g = new Graph()
t = 0
g.addexpr("sin(t)")
g.xexpr("cos(t)")
g.begin()
for(t=0; t<=2*PI+0.1; t=t+0.1){
g.plot(t)
}
g.flush()
Note that the arguments to ``g.line`` are doubles, and not chars as they are in ``g.plot()``.
----
.. method:: Graph.mark
Syntax:
``.mark(x, y)``
``.mark(x, y, "style")``
``.mark(x, y, "style", size)``
``.mark(x, y, "style", size, color, brush)``
Description:
Make a mark centered at the indicated position which does not
change size when window is zoomed or resized. The style is a single
character ``+, o, s, t, O, S, T, |, -`` where ``o,t,s`` stand for circle, triangle,
square and capitalized means filled. Default size is 12 points.
For the style, an integer index, 0-8, relative to the above list may
also be used.
----
.. method:: Graph.crosshair_action
Syntax:
``.crosshair_action("procedure_name")``
``.crosshair_action("procedure_name", vectorflag=0)``
``.crosshair_action("")``
Description:
While the crosshair is visible (left mouse button pressed) one
can type any key and the procedure will be executed with
three arguments added:
``procedure_name(x, y, c)``
where x and y are the coordinates of the crosshair (in model
coordinates) and c is the ascii code for the key pressed.
The procedure will be executed in the context of the object
where ``crosshair_action`` was executed.
When the optional vectorflag argument is 1, then, just prior
to each call of the *procedure_name* due to a keypress,
two temporary *objectref*'s are created and assigned to a
new ``Vector()`` and the line coordinate data is copied to those Vectors.
With this form the call to the procedure has two args added:
``procedure_name(i, c, $o3, $o4)``
where ``i`` is the index of the crosshair into the Vector.
If you wish the Vector data to persist then you can assign to
another objectvar before returning from the ``procedure_name``.
Note that one can copy any line to a Vector with this method whereas
the interpreter controlled ``Graph.dump("expr", y_objectref)`` is
limited to the current graphline of an ``addvar`` or ``addexpr``.
With an empty string arg, the existing action is removed.
.. seealso::
:ref:`gui_PickVector`, :func:`menu_tool`
----
.. method:: Graph.view_count
Syntax:
``.view_count()``
Description:
Returns number of views into this scene. (stdrun.hoc removes
scenes from the ``flush_list`` and ``graphList[]`` when this goes to
0. If no other ``objectvar`` points to the scene, it will be
freed.)
----
.. method:: Graph.unmap
Syntax:
``.unmap()``
Description:
Dismiss all windows that are a direct view into this scene.
(does not unmap boxes containing scenes.) ``.unmap`` is called
automatically when no hoc object variable references the Graph.
----
.. method:: Graph.printfile
Syntax:
``.printfile("filename")``
Description:
Print the first view of the graph as an encapsulated post script
file.
----
.. method:: Graph.menu_remove
Syntax:
``g.menu_remove("item name")``
Description:
Removes the named menu item from the Graph instance.
----
.. method:: Graph.exec_menu
Syntax:
``g.exec_menu("item name")``
Description:
Equivalent to by pressing and releasing one of the items in the
Graph menu with the right mouse button. This executes an action for
regular items, toggles for items like "Keep Lines", and specifies the
left mouse tool for radio buttons. The "item name" must be identical to
the string in the menu item, including spaces and case. Some items may
not work unless the graph is mapped to the screen. Selection is with respect
to the primary (first) view, eg selecting "View = plot" of a Grapher will
always refer to the view in the Grapher tool as opposed to other views of
the same graph created via the "NewView" menu item. Any items created
with :meth:`Graph.menu_action` or :meth:`Graph.menu_tool` are selectable with this
function.
Example:
.. code-block::
none
objref g
g = new Graph()
g.exec_menu("Keep Lines")
----
.. method:: Graph.menu_action
Syntax:
``.menu_action("label", "action")``
Description:
Add a menu item to the Graph popup menu. When pressed, the action will be
executed
Example:
.. code-block::
none
objref g
g = new Graph()
g.menu_action("Print File", "g.printfile(\"temp.eps\") system(\"lp temp.eps\")")
----
.. method:: Graph.menu_tool
Syntax:
``.menu_tool("label", "procedure_name")``
``.menu_tool("label", "procedure_name", "select_action")``
Description:
Add a selectable tool menu item to the Graph popup menu or else, if an
:func:`xpanel` is open, an :func:`xradiobutton` will be added to the panel having the
same action. (note: all menu_tool radiobuttons whether in the graph menu
or in a panel, are in the same telltalegroup, so selecting one deselects the
previous selection.)
If the third arg exists, the select_action will be executed when
the radioitem is pressed (if it is not already selected).
When selected, the item will be marked and the label will appear on
the window title bar (but not if the Graph is enclosed in a :func:`VBox` ).
When this tool is selected, pressing the left mouse
button, dragging the mouse, and releasing the left button, will cause
procedure_name to be called with four arguments: type, x, y, keystate.
x and y are the scene (model) coordinates of the mouse pointer, and type is
2 for press, 1 for dragging, and 3 for release. Keystate reflects the
state of control (bit 1), shift (bit 2), and meta (bit 3) keys, ie control
and shift down has a value of 3.
The rate of calls for dragging is of course dependent on the time it takes
to execute the procedure name.
Example:
.. code-block::
none
objref g
g = new Graph()
g.menu_tool("mouse events", "p")
proc p() {
print $1, $2, $3, $4
}
----
.. method:: Graph.gif
Syntax:
``g.gif("file.gif")``
``g.gif("file.gif", left, bottom, width, height)``
Description:
Display the gif image in model coordinates with lower left corner at 0,0
or indicated left, bottom coords. The width and height of the gif file are the
desired width and height of the image in model coordinates, by default they
are the pixel Width and Height of the gif file.
Example:
Suppose we have a gif with pixel width and height, wg and hg respectively.
Also suppose we want the gif pixel point (xg0, yg0) mapped to graph
model coordinate (x0, y0) and the gif pixel point (xg1, yg1) mapped to
graph model coordinate (x1, y1). Then the last four arguments to
g.gif should be:
.. code-block::
none
left = x0 - xg0*(x1-x0)/(xg1-xg0)
bottom = y0 - yg0*(y1-y0)/(yg1-yg0)
width = wg*(x1-x0)/(xg1-xg0)
height= hg*(y1-y0)/(yg1-yg0)
If, for example with xv, you have constructed a desired rectangle on the
gif and the info (xv controls/Windows/Image Info)presented is
Resolution: 377x420
Selection: 225x279 rectangle starting at 135,44
then use
.. code-block::
none
{wg=377 hg=420}
{xg0=135 yg0=420-(279+44) xg1=135+225 yg1=420-44}
.. warning::
In the single arg form, if the gif size is larger than the graph model
coodinates, the graph is resized to the size of the gif. This prevents
excessive use of memory and computation time when the graph size is on
the order of a gif pixel.
----
.. method:: Graph.view_info
Syntax:
``i = g.view_info()``
``val = g.view_info(i, case)``
``val = g.view_info(i, case, model_coord)``
Description:
Return information about the ith view.
With no args the return value is the view number where the mouse is.
If the mouse was not last in a view of g, the return value is -1. Therefore
this no arg function call should only be made on a mouse down event and
saved for handling the other mouse events. Note that the two arg cases
are generally constant between a mouse down and up event.
.. code-block::
none
case 1: // width
case 2: // height
case 3: // point width
case 4: // point height
case 5: // left
case 6: // right
case 7: // bottom
case 8: // top
case 9: // model x distance for one point
case 10: // model y distance for one point
The following cases (11 - 14) require a third argument
relative location means (0,0) is lower left and (1,1) is upper right.
case 11: // relative x location (from x model coord)
case 12: // relative y location (from y model coord)
case 13: // points from left (from x model coord)
case 14: // points from top (from y model coord)
Note: this last is from the top, not from the bottom.
case 15: // height of font in points
----
.. method:: Graph.view_size
Syntax:
``g.view_size(i, left, right, bottom, top)``
Description:
Specifies the model coordinates of the ith view of a Graph.
It is possible to use this in a :meth:`Graph.menu_tool` callback procedure.
----
.. method:: Graph.glyph
Syntax:
``g.glyph(glyphobject, x, y, scalex, scaley, angle, fixtype)``
Description:
Add the :func:`Glyph` object to the graph at indicated coordinates (the origin
of the Glyph will appear at x,y) first scaling the Glyph and then
rotating by the indicated angle in degrees. The last four arguments
are optional and have defaults of 1,1,0,0 respectively. Fixtype
refers to whether the glyph moves and scales with zooming and translation,
moves only with translation but does not scale, or neither moves nor
scales.
----
.. method:: Graph.simgraph
Syntax:
``g.simgraph()``
Description:
Adds all the :meth:`Graph.addvar` lines to a list managed by :class:`CVode` which
allows the local variable time step method to properly graph the lines.
See the implementation in share/lib/hoc/stdrun.hoc for usage.