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By default, Octave refreshes the plot window when a prompt is printed,
or when waiting for input. The
drawnow
function is used to cause a plot window to be updated.
Update figure windows and their children.
The event queue is flushed and any callbacks generated are executed.
With the optional argument "expose"
, only graphic objects are
updated and no other events or callbacks are processed.
The third calling form of drawnow
is for debugging and is
undocumented.
See also: refresh.
Only figures that are modified will be updated. The refresh
function can also be used to cause an update of the current figure, even if
it is not modified.
Refresh a figure, forcing it to be redrawn.
When called without an argument the current figure is redrawn. Otherwise, the figure with graphic handle h is redrawn.
See also: drawnow.
Normally, high-level plot functions like plot
or mesh
call
newplot
to determine whether the state of the target axes should be
initialized (the default) or if subsequent plots should be drawn on top of
previous ones. To have two plots drawn over one another, use the hold
function or manually change the axes nextplot
property. For example,
hold on; x = -10:0.1:10; plot (x, sin (x)); plot (x, cos (x)); hold off;
displays sine and cosine waves on the same axes. If the hold state is off, consecutive plotting commands like this will only display the last plot.
Prepare graphics engine to produce a new plot.
This function is called at the beginning of all high-level plotting
functions. It is not normally required in user programs. newplot
queries the "NextPlot"
field of the current figure and axes to
determine what to do.
Figure NextPlot | Action |
---|---|
"new" | Create a new figure and make it the current figure. |
"add" (default) | Add new graphic objects to the current figure. |
"replacechildren" | Delete child objects whose
HandleVisibility is set to "on" . Set NextPlot property to
"add" . This typically clears a figure, but leaves in place hidden
objects such as menubars. This is equivalent to clf . |
"replace" | Delete all child objects of the figure and
reset all figure properties to their defaults. However, the following
four properties are not reset: Position, Units, PaperPosition, PaperUnits.
This is equivalent to clf reset . |
Axes NextPlot | Action |
---|---|
"add" | Add new graphic objects to the current axes. This
is equivalent to hold on . |
"replacechildren" | Delete child objects whose
HandleVisibility is set to "on" , but leave axes properties
unmodified. This typically clears a plot, but preserves special settings
such as log scaling for axes. This is equivalent to cla . |
"replace" (default) | Delete all child objects of the
axes and reset all axes properties to their defaults. However, the
following properties are not reset: Position, Units. This is equivalent
to cla reset . |
If the optional input hfig or hax is given then prepare the specified figure or axes rather than the current figure and axes.
The optional return value hax is a graphics handle to the created axes object (not figure).
Caution: Calling newplot
may change the current figure and
current axes.
Toggle or set the "hold"
state of the plotting engine which
determines whether new graphic objects are added to the plot or replace
the existing objects.
hold on
Retain plot data and settings so that subsequent plot commands are displayed on a single graph. Line color and line style are advanced for each new plot added.
hold all (deprecated)
Equivalent to hold on
.
hold off
Restore default graphics settings which clear the graph and reset axes properties before each new plot command. (default).
hold
Toggle the current hold state.
When given the additional argument hax, the hold state is modified
for this axes rather than the current axes returned by gca
.
To query the current hold state use the ishold
function.
Return true if the next plot will be added to the current plot, or false if the plot device will be cleared before drawing the next plot.
If the first argument is an axes handle hax or figure handle hfig then operate on this plot rather than the current one.
To clear the current figure, call the clf
function. To clear the
current axis, call the cla
function. To bring the current figure
to the top of the window stack, call the shg
function. To delete
a graphics object, call delete
on its index. To close the
figure window, call the close
function.
Clear the current figure window.
clf
operates by deleting child graphics objects with visible
handles (HandleVisibility = "on"
).
If the optional argument "reset"
is specified, delete all child
objects including those with hidden handles and reset all figure
properties to their defaults. However, the following properties are not
reset: Position, Units, PaperPosition, PaperUnits.
If the first argument hfig is a figure handle, then operate on
this figure rather than the current figure returned by gcf
.
The optional return value h is the graphics handle of the figure window that was cleared.
Clear the current or specified (hax) axes object.
cla
operates by deleting child graphic objects with visible
handles (HandleVisibility
= "on"
). This typically clears the
axes of any visual objects, but leaves in place axes limits, tick marks and
labels, camera view, etc. In addition, the automatic coloring and styling
of lines is reset by changing the axes properties ColorOrderIndex
,
LinestyleOrderIndex
to 1.
If the optional argument "reset"
is specified, delete all child
objects, including those with hidden handles, and reset all axes properties
to their defaults. However, the following properties are not reset:
Position
, Units
.
If the first argument hax is an axes handle, then operate on
this axes rather than the current axes returned by gca
.
Show the graph window.
This function makes the current figure visible, and places it on top of of all other plot windows.
Programming Note: shg
is equivalent to figure (gcf)
assuming
that a current figure exists.
Delete the named file or graphics handle.
file may contain globbing patterns such as ‘*’. Multiple files to be deleted may be specified in the same function call.
handle may be a scalar or vector of graphic handles to delete.
Programming Note: Deleting graphics objects is the proper way to remove features from a plot without clearing the entire figure.
Close figure window(s).
When called with no arguments, close the current figure. This is equivalent
to close (gcf)
. If the input h is a graphic handle, or vector
of graphics handles, then close each figure in h. The figure to
close may also be specified by name figname which is matched against
the "Name"
property of all figures.
If the argument "all"
is given then all figures with visible handles
(HandleVisibility = "on"
) are closed.
If the additional argument "hidden"
is given then all figures,
including hidden ones, are closed.
If the additional argument "force"
is given then figures are closed
even when "closerequestfcn"
has been altered to prevent closing the
window.
Implementation Note: close
operates by making the handle h the
current figure, and then calling the function specified by the
"closerequestfcn"
property of the figure. By default, the function
closereq
is used. It is possible that the function invoked will
delay or abort removing the figure. To remove a figure without executing
any callback functions use delete
. When writing a callback function
to close a window do not use close
to avoid recursion.
Next: Use of the interpreter
Property, Previous: Manipulation of Plot Objects, Up: High-Level Plotting [Contents][Index]