File: Graphics-Objects.html

package info (click to toggle)
octave 4.0.3-3
links: PTS, VCS
area: main
in suites: stretch
size: 94,200 kB
ctags: 52,925
sloc: cpp: 316,850; ansic: 43,469; fortran: 23,670; sh: 13,805; yacc: 8,204; objc: 7,939; lex: 3,631; java: 2,127; makefile: 1,746; perl: 1,022; awk: 988
file content (674 lines) | stat: -rw-r--r-- 34,456 bytes
parent folder | download | duplicates (2)
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Created by GNU Texinfo 6.1, http://www.gnu.org/software/texinfo/ -->
<head>
<title>GNU Octave: Graphics Objects</title>

<meta name="description" content="GNU Octave: Graphics Objects">
<meta name="keywords" content="GNU Octave: Graphics Objects">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Graphics-Data-Structures.html#Graphics-Data-Structures" rel="up" title="Graphics Data Structures">
<link href="Graphics-Object-Properties.html#Graphics-Object-Properties" rel="next" title="Graphics Object Properties">
<link href="Introduction-to-Graphics-Structures.html#Introduction-to-Graphics-Structures" rel="prev" title="Introduction to Graphics Structures">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.indentedblock {margin-right: 0em}
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smalllisp {margin-left: 3.2em}
kbd {font-style: oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nolinebreak {white-space: nowrap}
span.roman {font-family: initial; font-weight: normal}
span.sansserif {font-family: sans-serif; font-weight: normal}
ul.no-bullet {list-style: none}
-->
</style>


</head>

<body lang="en">
<a name="Graphics-Objects"></a>
<div class="header">
<p>
Next: <a href="Graphics-Object-Properties.html#Graphics-Object-Properties" accesskey="n" rel="next">Graphics Object Properties</a>, Previous: <a href="Introduction-to-Graphics-Structures.html#Introduction-to-Graphics-Structures" accesskey="p" rel="prev">Introduction to Graphics Structures</a>, Up: <a href="Graphics-Data-Structures.html#Graphics-Data-Structures" accesskey="u" rel="up">Graphics Data Structures</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Graphics-Objects-1"></a>
<h4 class="subsection">15.3.2 Graphics Objects</h4>
<a name="index-graphics-objects"></a>

<p>The hierarchy of graphics objects was explained above.
See <a href="Introduction-to-Graphics-Structures.html#Introduction-to-Graphics-Structures">Introduction to Graphics Structures</a>.  Here the
specific objects are described, and the properties contained in
these objects are discussed.  Keep in mind that
graphics objects are always referenced by <em>handle</em>.
</p>
<dl compact="compact">
<dt>root figure</dt>
<dd><a name="index-root-figure-graphics-object"></a>
<a name="index-graphics-object_002c-root-figure"></a>
<p>the top level of the hierarchy and the parent of all figure objects.
The handle index of the root figure is 0.
</p>
</dd>
<dt>figure</dt>
<dd><a name="index-figure-graphics-object"></a>
<a name="index-graphics-object_002c-figure"></a>
<p>A figure window.
</p>
</dd>
<dt>axes</dt>
<dd><a name="index-axes-graphics-object"></a>
<a name="index-graphics-object_002c-axes"></a>
<p>A set of axes.  This object is a child of a figure object and may be a
parent of line, text, image, patch, or surface objects.
</p>
</dd>
<dt>line</dt>
<dd><a name="index-line-graphics-object"></a>
<a name="index-graphics-object_002c-line"></a>
<p>A line in two or three dimensions.
</p>
</dd>
<dt>text</dt>
<dd><a name="index-text-graphics-object"></a>
<a name="index-graphics-object_002c-text"></a>
<p>Text annotations.
</p>
</dd>
<dt>image</dt>
<dd><a name="index-image-graphics-object"></a>
<a name="index-graphics-object_002c-image"></a>
<p>A bitmap image.
</p>
</dd>
<dt>patch</dt>
<dd><a name="index-patch-graphics-object"></a>
<a name="index-graphics-object_002c-patch"></a>
<p>A filled polygon, currently limited to two dimensions.
</p>
</dd>
<dt>surface</dt>
<dd><a name="index-surface-graphics-object"></a>
<a name="index-graphics-object_002c-surface"></a>
<p>A three-dimensional surface.
</p></dd>
</dl>

<a name="Creating-Graphics-Objects"></a>
<h4 class="subsubsection">15.3.2.1 Creating Graphics Objects</h4>
<a name="index-creating-graphics-objects"></a>

<p>You can create any graphics object primitive by calling the function of the
same name as the object; In other words, <code>figure</code>, <code>axes</code>,
<code>line</code>, <code>text</code>, <code>image</code>, <code>patch</code>, and <code>surface</code>
functions.  These fundamental graphic objects automatically become children
of the current axes object as if <code>hold on</code> was in place.  Seperately, axes
will automatically become children of the current figure object and figures
will become children of the root object 0.
</p>
<p>If this auto-joining feature is not desired then it is important to call
<code>newplot</code> first to prepare a new figure and axes for plotting.
Alternatively, the easier way is to call a high-level graphics routine which
will both create the plot and then populate it with low-level graphics objects.
Instead of calling <code>line</code>, use <code>plot</code>.  Or use <code>surf</code> instead of
<code>surface</code>.  Or use <code>fill</code> instead of <code>patch</code>.
</p>
<a name="XREFaxes"></a><dl>
<dt><a name="index-axes"></a>Function File: <em></em> <strong>axes</strong> <em>()</em></dt>
<dt><a name="index-axes-1"></a>Function File: <em></em> <strong>axes</strong> <em>(<var>property</var>, <var>value</var>, &hellip;)</em></dt>
<dt><a name="index-axes-2"></a>Function File: <em></em> <strong>axes</strong> <em>(<var>hax</var>)</em></dt>
<dt><a name="index-axes-3"></a>Function File: <em><var>h</var> =</em> <strong>axes</strong> <em>(&hellip;)</em></dt>
<dd><p>Create an axes object and return a handle to it, or set the current axes
to <var>hax</var>.
</p>
<p>Called without any arguments, or with <var>property</var>/<var>value</var> pairs,
construct a new axes.  For accepted properties and corresponding
values, see <a href="#XREFset">set</a>.
</p>
<p>Called with a single axes handle argument <var>hax</var>, the function makes
<var>hax</var> the current axis.  It also restacks the axes in the
corresponding figure so that <var>hax</var> is the first entry in the list
of children.  This causes <var>hax</var> to be displayed on top of any other
axes objects (Z-order stacking).
</p>

<p><strong>See also:</strong> <a href="#XREFgca">gca</a>, <a href="#XREFset">set</a>, <a href="#XREFget">get</a>.
</p></dd></dl>


<a name="XREFline"></a><dl>
<dt><a name="index-line"></a>Function File: <em></em> <strong>line</strong> <em>()</em></dt>
<dt><a name="index-line-1"></a>Function File: <em></em> <strong>line</strong> <em>(<var>x</var>, <var>y</var>)</em></dt>
<dt><a name="index-line-2"></a>Function File: <em></em> <strong>line</strong> <em>(<var>x</var>, <var>y</var>, <var>property</var>, <var>value</var>, &hellip;)</em></dt>
<dt><a name="index-line-3"></a>Function File: <em></em> <strong>line</strong> <em>(<var>x</var>, <var>y</var>, <var>z</var>)</em></dt>
<dt><a name="index-line-4"></a>Function File: <em></em> <strong>line</strong> <em>(<var>x</var>, <var>y</var>, <var>z</var>, <var>property</var>, <var>value</var>, &hellip;)</em></dt>
<dt><a name="index-line-5"></a>Function File: <em></em> <strong>line</strong> <em>(<var>property</var>, <var>value</var>, &hellip;)</em></dt>
<dt><a name="index-line-6"></a>Function File: <em></em> <strong>line</strong> <em>(<var>hax</var>, &hellip;)</em></dt>
<dt><a name="index-line-7"></a>Function File: <em><var>h</var> =</em> <strong>line</strong> <em>(&hellip;)</em></dt>
<dd><p>Create line object from <var>x</var> and <var>y</var> (and possibly <var>z</var>) and
insert in the current axes.
</p>
<p>Multiple property-value pairs may be specified for the line object, but they
must appear in pairs.
</p>
<p>If the first argument <var>hax</var> is an axes handle, then plot into this axis,
rather than the current axes returned by <code>gca</code>.
</p>
<p>The optional return value <var>h</var> is a graphics handle (or vector of handles)
to the line objects created.
</p>

<p><strong>See also:</strong> <a href="Displaying-Images.html#XREFimage">image</a>, <a href="#XREFpatch">patch</a>, <a href="Two_002ddimensional-Geometric-Shapes.html#XREFrectangle">rectangle</a>, <a href="#XREFsurface">surface</a>, <a href="Plot-Annotations.html#XREFtext">text</a>.
</p></dd></dl>


<a name="XREFpatch"></a><dl>
<dt><a name="index-patch"></a>Function File: <em></em> <strong>patch</strong> <em>()</em></dt>
<dt><a name="index-patch-1"></a>Function File: <em></em> <strong>patch</strong> <em>(<var>x</var>, <var>y</var>, <var>c</var>)</em></dt>
<dt><a name="index-patch-2"></a>Function File: <em></em> <strong>patch</strong> <em>(<var>x</var>, <var>y</var>, <var>z</var>, <var>c</var>)</em></dt>
<dt><a name="index-patch-3"></a>Function File: <em></em> <strong>patch</strong> <em>(<var>fv</var>)</em></dt>
<dt><a name="index-patch-4"></a>Function File: <em></em> <strong>patch</strong> <em>(&quot;Faces&quot;, <var>faces</var>, &quot;Vertices&quot;, <var>verts</var>, &hellip;)</em></dt>
<dt><a name="index-patch-5"></a>Function File: <em></em> <strong>patch</strong> <em>(&hellip;, <var>prop</var>, <var>val</var>, &hellip;)</em></dt>
<dt><a name="index-patch-6"></a>Function File: <em></em> <strong>patch</strong> <em>(<var>hax</var>, &hellip;)</em></dt>
<dt><a name="index-patch-7"></a>Function File: <em><var>h</var> =</em> <strong>patch</strong> <em>(&hellip;)</em></dt>
<dd><p>Create patch object in the current axes with vertices at locations
(<var>x</var>, <var>y</var>) and of color <var>c</var>.
</p>
<p>If the vertices are matrices of size MxN then each polygon patch
has M vertices and a total of N polygons will be created.  If some polygons
do not have M vertices use NaN to represent &quot;no vertex&quot;.  If the <var>z</var>
input is present then 3-D patches will be created.
</p>
<p>The color argument <var>c</var> can take many forms.  To create polygons
which all share a single color use a string value (e.g., <code>&quot;r&quot;</code> for
red), a scalar value which is scaled by <code>caxis</code> and indexed into the
current colormap, or a 3-element RGB vector with the precise TrueColor.
</p>
<p>If <var>c</var> is a vector of length N then the ith polygon will have a color
determined by scaling entry <var>c</var>(i) according to <code>caxis</code> and then
indexing into the current colormap.  More complicated coloring situations
require directly manipulating patch property/value pairs.
</p>
<p>Instead of specifying polygons by matrices <var>x</var> and <var>y</var>, it is
possible to present a unique list of vertices and then a list of polygon
faces created from those vertices.  In this case the
<code>&quot;Vertices&quot;</code> matrix will be an Nx2 (2-D patch) or
Nx3 (3-D patch).  The MxN <code>&quot;Faces&quot;</code> matrix
describes M polygons having N vertices&mdash;each row describes a
single polygon and each column entry is an index into the
<code>&quot;Vertices&quot;</code> matrix to identify a vertex.  The patch object
can be created by directly passing the property/value pairs
<code>&quot;Vertices&quot;</code>/<var>verts</var>, <code>&quot;Faces&quot;</code>/<var>faces</var> as
inputs.
</p>
<p>A third input form is to create a structure <var>fv</var> with the fields
<code>&quot;vertices&quot;</code>, <code>&quot;faces&quot;</code>, and optionally
<code>&quot;facevertexcdata&quot;</code>.
</p>
<p>If the first argument <var>hax</var> is an axes handle, then plot into this axis,
rather than the current axes returned by <code>gca</code>.
</p>
<p>The optional return value <var>h</var> is a graphics handle to the created patch
object.
</p>
<p>Implementation Note: Patches are highly configurable objects.  To truly
customize them requires setting patch properties directly.  Useful patch
properties are: <code>&quot;cdata&quot;</code>, <code>&quot;edgecolor&quot;</code>,
<code>&quot;facecolor&quot;</code>, <code>&quot;faces&quot;</code>, <code>&quot;facevertexcdata&quot;</code>.
</p>
<p><strong>See also:</strong> <a href="Two_002dDimensional-Plots.html#XREFfill">fill</a>, <a href="#XREFget">get</a>, <a href="#XREFset">set</a>.
</p></dd></dl>


<a name="XREFsurface"></a><dl>
<dt><a name="index-surface"></a>Function File: <em></em> <strong>surface</strong> <em>(<var>x</var>, <var>y</var>, <var>z</var>, <var>c</var>)</em></dt>
<dt><a name="index-surface-1"></a>Function File: <em></em> <strong>surface</strong> <em>(<var>x</var>, <var>y</var>, <var>z</var>)</em></dt>
<dt><a name="index-surface-2"></a>Function File: <em></em> <strong>surface</strong> <em>(<var>z</var>, <var>c</var>)</em></dt>
<dt><a name="index-surface-3"></a>Function File: <em></em> <strong>surface</strong> <em>(<var>z</var>)</em></dt>
<dt><a name="index-surface-4"></a>Function File: <em></em> <strong>surface</strong> <em>(&hellip;, <var>prop</var>, <var>val</var>, &hellip;)</em></dt>
<dt><a name="index-surface-5"></a>Function File: <em></em> <strong>surface</strong> <em>(<var>hax</var>, &hellip;)</em></dt>
<dt><a name="index-surface-6"></a>Function File: <em><var>h</var> =</em> <strong>surface</strong> <em>(&hellip;)</em></dt>
<dd><p>Create a surface graphic object given matrices <var>x</var> and <var>y</var> from
<code>meshgrid</code> and a matrix of values <var>z</var> corresponding to the
<var>x</var> and <var>y</var> coordinates of the surface.
</p>
<p>If <var>x</var> and <var>y</var> are vectors, then a typical vertex is
(<var>x</var>(j), <var>y</var>(i), <var>z</var>(i,j)).  Thus, columns of <var>z</var> correspond
to different <var>x</var> values and rows of <var>z</var> correspond to different
<var>y</var> values.  If only a single input <var>z</var> is given then <var>x</var> is
taken to be <code>1:rows (<var>z</var>)</code> and <var>y</var> is
<code>1:columns (<var>z</var>)</code>.
</p>
<p>Any property/value input pairs are assigned to the surface object.
</p>
<p>If the first argument <var>hax</var> is an axes handle, then plot into this axis,
rather than the current axes returned by <code>gca</code>.
</p>
<p>The optional return value <var>h</var> is a graphics handle to the created
surface object.
</p>
<p><strong>See also:</strong> <a href="Three_002dDimensional-Plots.html#XREFsurf">surf</a>, <a href="Three_002dDimensional-Plots.html#XREFmesh">mesh</a>, <a href="#XREFpatch">patch</a>, <a href="#XREFline">line</a>.
</p></dd></dl>


<a name="Handle-Functions"></a>
<h4 class="subsubsection">15.3.2.2 Handle Functions</h4>
<a name="index-handle-functions"></a>

<p>To determine whether a variable is a graphics object index, or an index
to an axes or figure, use the functions <code>ishandle</code>, <code>isaxes</code>, and
<code>isfigure</code>.
</p>
<a name="XREFishandle"></a><dl>
<dt><a name="index-ishandle"></a>Built-in Function: <em></em> <strong>ishandle</strong> <em>(<var>h</var>)</em></dt>
<dd><p>Return true if <var>h</var> is a graphics handle and false otherwise.
</p>
<p><var>h</var> may also be a matrix of handles in which case a logical array is
returned that is true where the elements of <var>h</var> are graphics handles and
false where they are not.
</p>
<p><strong>See also:</strong> <a href="#XREFisaxes">isaxes</a>, <a href="#XREFisfigure">isfigure</a>.
</p></dd></dl>


<a name="XREFishghandle"></a><dl>
<dt><a name="index-ishghandle"></a>Function File: <em></em> <strong>ishghandle</strong> <em>(<var>h</var>)</em></dt>
<dd><p>Return true if <var>h</var> is a graphics handle and false otherwise.
</p>
<p>This function is equivalent to <code>ishandle</code> and is provided for
compatibility with <small>MATLAB</small>.
</p>
<p><strong>See also:</strong> <a href="#XREFishandle">ishandle</a>.
</p></dd></dl>


<a name="XREFisaxes"></a><dl>
<dt><a name="index-isaxes"></a>Function File: <em></em> <strong>isaxes</strong> <em>(<var>h</var>)</em></dt>
<dd><p>Return true if <var>h</var> is an axes graphics handle and false otherwise.
</p>
<p>If <var>h</var> is a matrix then return a logical array which is true where the
elements of <var>h</var> are axes graphics handles and false where they are not.
</p>
<p><strong>See also:</strong> <a href="#XREFisaxes">isaxes</a>, <a href="#XREFishandle">ishandle</a>.
</p></dd></dl>


<a name="XREFisfigure"></a><dl>
<dt><a name="index-isfigure"></a>Function File: <em></em> <strong>isfigure</strong> <em>(<var>h</var>)</em></dt>
<dd><p>Return true if <var>h</var> is a figure graphics handle and false otherwise.
</p>
<p>If <var>h</var> is a matrix then return a logical array which is true where the
elements of <var>h</var> are figure graphics handles and false where they are not.
</p>
<p><strong>See also:</strong> <a href="#XREFisaxes">isaxes</a>, <a href="#XREFishandle">ishandle</a>.
</p></dd></dl>


<p>The function <code>gcf</code> returns an index to the current figure object,
or creates one if none exists.  Similarly, <code>gca</code> returns the
current axes object, or creates one (and its parent figure object) if
none exists.
</p>
<a name="XREFgcf"></a><dl>
<dt><a name="index-gcf"></a>Function File: <em><var>h</var> =</em> <strong>gcf</strong> <em>()</em></dt>
<dd><p>Return a handle to the current figure.
</p>
<p>The current figure is the default target for graphics output.  If multiple
figures exist, <code>gcf</code> returns the last created figure or the last figure
that was clicked on with the mouse.
</p>
<p>If a current figure does not exist, create one and return its handle.  The
handle may then be used to examine or set properties of the figure.  For
example,
</p>
<div class="example">
<pre class="example">fplot (@sin, [-10, 10]);
fig = gcf ();
set (fig, &quot;numbertitle&quot;, &quot;off&quot;, &quot;name&quot;, &quot;sin plot&quot;)
</pre></div>

<p>plots a sine wave, finds the handle of the current figure, and then
renames the figure window to describe the contents.
</p>
<p>Note: To find the current figure without creating a new one if it does not
exist, query the <code>&quot;CurrentFigure&quot;</code> property of the root graphics
object.
</p>
<div class="example">
<pre class="example">get (0, &quot;currentfigure&quot;);
</pre></div>


<p><strong>See also:</strong> <a href="#XREFgca">gca</a>, <a href="#XREFgco">gco</a>, <a href="Callbacks.html#XREFgcbf">gcbf</a>, <a href="Callbacks.html#XREFgcbo">gcbo</a>, <a href="#XREFget">get</a>, <a href="#XREFset">set</a>.
</p></dd></dl>


<a name="XREFgca"></a><dl>
<dt><a name="index-gca"></a>Function File: <em><var>h</var> =</em> <strong>gca</strong> <em>()</em></dt>
<dd><p>Return a handle to the current axis object.
</p>
<p>The current axis is the default target for graphics output.  In the case
of a figure with multiple axes, <code>gca</code> returns the last created axes
or the last axes that was clicked on with the mouse.
</p>
<p>If no current axes object exists, create one and return its handle.  The
handle may then be used to examine or set properties of the axes.  For
example,
</p>
<div class="example">
<pre class="example">ax = gca ();
set (ax, &quot;position&quot;, [0.5, 0.5, 0.5, 0.5]);
</pre></div>

<p>creates an empty axes object and then changes its location and size in the
figure window.
</p>
<p>Note: To find the current axis without creating a new axes object if it
does not exist, query the <code>&quot;CurrentAxes&quot;</code> property of a figure.
</p>
<div class="example">
<pre class="example">get (gcf, &quot;currentaxes&quot;);
</pre></div>

<p><strong>See also:</strong> <a href="#XREFgcf">gcf</a>, <a href="#XREFgco">gco</a>, <a href="Callbacks.html#XREFgcbf">gcbf</a>, <a href="Callbacks.html#XREFgcbo">gcbo</a>, <a href="#XREFget">get</a>, <a href="#XREFset">set</a>.
</p></dd></dl>


<a name="XREFgco"></a><dl>
<dt><a name="index-gco"></a>Function File: <em><var>h</var> =</em> <strong>gco</strong> <em>()</em></dt>
<dt><a name="index-gco-1"></a>Function File: <em><var>h</var> =</em> <strong>gco</strong> <em>(<var>fig</var>)</em></dt>
<dd><p>Return a handle to the current object of the current figure, or a handle
to the current object of the figure with handle <var>fig</var>.
</p>
<p>The current object of a figure is the object that was last clicked on.  It
is stored in the <code>&quot;CurrentObject&quot;</code> property of the target figure.
</p>
<p>If the last mouse click did not occur on any child object of the figure,
then the current object is the figure itself.
</p>
<p>If no mouse click occurred in the target figure, this function returns an
empty matrix.
</p>
<p>Programming Note: The value returned by this function is not necessarily the
same as the one returned by <code>gcbo</code> during callback execution.  An
executing callback can be interrupted by another callback and the current
object may be changed.
</p>

<p><strong>See also:</strong> <a href="Callbacks.html#XREFgcbo">gcbo</a>, <a href="#XREFgca">gca</a>, <a href="#XREFgcf">gcf</a>, <a href="Callbacks.html#XREFgcbf">gcbf</a>, <a href="#XREFget">get</a>, <a href="#XREFset">set</a>.
</p></dd></dl>


<p>The <code>get</code> and <code>set</code> functions may be used to examine and set
properties for graphics objects.  For example,
</p>
<div class="example">
<pre class="example">get (0)
    &rArr; ans =
       {
         type = root
         currentfigure = [](0x0)
         children = [](0x0)
         visible = on
         &hellip;
       }
</pre></div>

<p>returns a structure containing all the properties of the root figure.
As with all functions in Octave, the structure is returned by value, so
modifying it will not modify the internal root figure plot object.  To
do that, you must use the <code>set</code> function.  Also, note that in this
case, the <code>currentfigure</code> property is empty, which indicates that
there is no current figure window.
</p>
<p>The <code>get</code> function may also be used to find the value of a single
property.  For example,
</p>
<div class="example">
<pre class="example">get (gca (), &quot;xlim&quot;)
    &rArr; [ 0 1 ]
</pre></div>

<p>returns the range of the x-axis for the current axes object in the
current figure.
</p>
<p>To set graphics object properties, use the set function.  For example,
</p>
<div class="example">
<pre class="example">set (gca (), &quot;xlim&quot;, [-10, 10]);
</pre></div>

<p>sets the range of the x-axis for the current axes object in the current
figure to &lsquo;<samp>[-10, 10]</samp>&rsquo;.
</p>
<p>Default property values can also be queried if the <code>set</code> function is
called without a value argument.  When only one argument is given (a graphic
handle) then a structure with defaults for all properties of the given object
type is returned.  For example,
</p>
<div class="example">
<pre class="example">set (gca ())
</pre></div>

<p>returns a structure containing the default property values for axes objects.
If <code>set</code> is called with two arguments (a graphic handle and a property
name) then only the defaults for the requested property are returned.
</p>
<a name="XREFget"></a><dl>
<dt><a name="index-get"></a>Built-in Function: <em><var>val</var> =</em> <strong>get</strong> <em>(<var>h</var>)</em></dt>
<dt><a name="index-get-1"></a>Built-in Function: <em><var>val</var> =</em> <strong>get</strong> <em>(<var>h</var>, <var>p</var>)</em></dt>
<dd><p>Return the value of the named property <var>p</var> from the graphics handle
<var>h</var>.
</p>
<p>If <var>p</var> is omitted, return the complete property list for <var>h</var>.
</p>
<p>If <var>h</var> is a vector, return a cell array including the property values or
lists respectively.
</p>
<p><strong>See also:</strong> <a href="#XREFset">set</a>.
</p></dd></dl>


<a name="XREFset"></a><dl>
<dt><a name="index-set"></a>Built-in Function: <em></em> <strong>set</strong> <em>(<var>h</var>, <var>property</var>, <var>value</var>, &hellip;)</em></dt>
<dt><a name="index-set-1"></a>Built-in Function: <em></em> <strong>set</strong> <em>(<var>h</var>, <var>properties</var>, <var>values</var>)</em></dt>
<dt><a name="index-set-2"></a>Built-in Function: <em></em> <strong>set</strong> <em>(<var>h</var>, <var>pv</var>)</em></dt>
<dt><a name="index-set-3"></a>Built-in Function: <em><var>value_list</var> =</em> <strong>set</strong> <em>(<var>h</var>, <var>property</var>)</em></dt>
<dt><a name="index-set-4"></a>Built-in Function: <em><var>all_value_list</var> =</em> <strong>set</strong> <em>(<var>h</var>)</em></dt>
<dd><p>Set named property values for the graphics handle (or vector of graphics
handles) <var>h</var>.
</p>
<p>There are three ways to give the property names and values:
</p>
<ul>
<li> as a comma separated list of <var>property</var>, <var>value</var> pairs

<p>Here, each <var>property</var> is a string containing the property name, each
<var>value</var> is a value of the appropriate type for the property.
</p>
</li><li> as a cell array of strings <var>properties</var> containing property names
and a cell array <var>values</var> containing property values.

<p>In this case, the number of columns of <var>values</var> must match the number of
elements in <var>properties</var>.  The first column of <var>values</var> contains
values for the first entry in <var>properties</var>, etc.  The number of rows of
<var>values</var> must be 1 or match the number of elements of <var>h</var>.  In the
first case, each handle in <var>h</var> will be assigned the same values.  In the
latter case, the first handle in <var>h</var> will be assigned the values from
the first row of <var>values</var> and so on.
</p>
</li><li> as a structure array <var>pv</var>

<p>Here, the field names of <var>pv</var> represent the property names, and the field
values give the property values.  In contrast to the previous case, all
elements of <var>pv</var> will be set in all handles in <var>h</var> independent of
the dimensions of <var>pv</var>.
</p></li></ul>

<p><code>set</code> is also used to query the list of values a named property will
take.  <code><var>clist</var> = set (<var>h</var>, &quot;property&quot;)</code> will return the list
of possible values for <code>&quot;property&quot;</code> in the cell list <var>clist</var>.
If no output variable is used then the list is formatted and printed to the
screen.
</p>
<p>If no property is specified (<code><var>slist</var> = set (<var>h</var>)</code>) then a
structure <var>slist</var> is returned where the fieldnames are the properties of
the object <var>h</var> and the fields are the list of possible values for each
property.  If no output variable is used then the list is formatted and
printed to the screen.
</p>
<p>For example,
</p>
<div class="example">
<pre class="example">hf = figure ();
set (hf, &quot;paperorientation&quot;)
&rArr;  paperorientation:  [ landscape | {portrait} | rotated ]
</pre></div>

<p>shows the paperorientation property can take three values with the default
being <code>&quot;portrait&quot;</code>.
</p>
<p><strong>See also:</strong> <a href="#XREFget">get</a>.
</p></dd></dl>


<a name="XREFancestor"></a><dl>
<dt><a name="index-ancestor"></a>Function File: <em><var>parent</var> =</em> <strong>ancestor</strong> <em>(<var>h</var>, <var>type</var>)</em></dt>
<dt><a name="index-ancestor-1"></a>Function File: <em><var>parent</var> =</em> <strong>ancestor</strong> <em>(<var>h</var>, <var>type</var>, &quot;toplevel&quot;)</em></dt>
<dd><p>Return the first ancestor of handle object <var>h</var> whose type matches
<var>type</var>, where <var>type</var> is a character string.
</p>
<p>If <var>type</var> is a cell array of strings, return the first parent whose
type matches any of the given type strings.
</p>
<p>If the handle object <var>h</var> itself is of type <var>type</var>, return <var>h</var>.
</p>
<p>If <code>&quot;toplevel&quot;</code> is given as a third argument, return the highest
parent in the object hierarchy that matches the condition, instead
of the first (nearest) one.
</p>
<p><strong>See also:</strong> <a href="Searching-Properties.html#XREFfindobj">findobj</a>, <a href="Searching-Properties.html#XREFfindall">findall</a>, <a href="#XREFallchild">allchild</a>.
</p></dd></dl>


<a name="XREFallchild"></a><dl>
<dt><a name="index-allchild"></a>Function File: <em><var>h</var> =</em> <strong>allchild</strong> <em>(<var>handles</var>)</em></dt>
<dd><p>Find all children, including hidden children, of a graphics object.
</p>
<p>This function is similar to <code>get (h, &quot;children&quot;)</code>, but also returns
hidden objects (HandleVisibility = <code>&quot;off&quot;</code>).
</p>
<p>If <var>handles</var> is a scalar, <var>h</var> will be a vector.  Otherwise,
<var>h</var> will be a cell matrix of the same size as <var>handles</var> and each
cell will contain a vector of handles.
</p>
<p><strong>See also:</strong> <a href="Searching-Properties.html#XREFfindall">findall</a>, <a href="Searching-Properties.html#XREFfindobj">findobj</a>, <a href="#XREFget">get</a>, <a href="#XREFset">set</a>.
</p></dd></dl>


<a name="XREFfindfigs"></a><dl>
<dt><a name="index-findfigs"></a>Function File: <em></em> <strong>findfigs</strong> <em>()</em></dt>
<dd><p>Find all visible figures that are currently off the screen and move them
onto the screen.
</p>
<p><strong>See also:</strong> <a href="#XREFallchild">allchild</a>, <a href="Multiple-Plot-Windows.html#XREFfigure">figure</a>, <a href="#XREFget">get</a>, <a href="#XREFset">set</a>.
</p></dd></dl>


<a name="index-saving-graphics-objects"></a>
<a name="index-graphics-objects_002c-saving"></a>

<p>Figures can be printed or saved in many graphics formats with <code>print</code> and
<code>saveas</code>.  Occasionally, however, it may be useful to save the original
Octave handle graphic directly so that further modifications can be made such
as modifying a title or legend.
</p>
<p>This can be accomplished with the following functions by
</p>
<div class="example">
<pre class="example">fig_struct = hdl2struct (gcf);
save myplot.fig -struct fig_struct;
&hellip;
fig_struct = load (&quot;myplot.fig&quot;);
struct2hdl (fig_struct);
</pre></div>

<a name="XREFhdl2struct"></a><dl>
<dt><a name="index-hdl2struct"></a>Function File: <em><var>s</var> =</em> <strong>hdl2struct</strong> <em>(<var>h</var>)</em></dt>
<dd><p>Return a structure, <var>s</var>, whose fields describe the properties
of the object, and its children, associated with the handle, <var>h</var>.
</p>
<p>The fields of the structure <var>s</var> are <code>&quot;type&quot;</code>, <code>&quot;handle&quot;</code>,
<code>&quot;properties&quot;</code>, <code>&quot;children&quot;</code>, and <code>&quot;special&quot;</code>.
</p>
<p><strong>See also:</strong> <a href="#XREFstruct2hdl">struct2hdl</a>, <a href="Printing-and-Saving-Plots.html#XREFhgsave">hgsave</a>, <a href="Searching-Properties.html#XREFfindobj">findobj</a>.
</p></dd></dl>


<a name="XREFstruct2hdl"></a><dl>
<dt><a name="index-struct2hdl"></a>Function File: <em><var>h</var> =</em> <strong>struct2hdl</strong> <em>(<var>s</var>)</em></dt>
<dt><a name="index-struct2hdl-1"></a>Function File: <em><var>h</var> =</em> <strong>struct2hdl</strong> <em>(<var>s</var>, <var>p</var>)</em></dt>
<dt><a name="index-struct2hdl-2"></a>Function File: <em><var>h</var> =</em> <strong>struct2hdl</strong> <em>(<var>s</var>, <var>p</var>, <var>hilev</var>)</em></dt>
<dd><p>Construct a graphics handle object <var>h</var> from the structure <var>s</var>.
</p>
<p>The structure must contain the fields <code>&quot;handle&quot;</code>, <code>&quot;type&quot;</code>,
<code>&quot;children&quot;</code>, <code>&quot;properties&quot;</code>, and <code>&quot;special&quot;</code>.
</p>
<p>If the handle of an existing figure or axes is specified, <var>p</var>, the new
object will be created as a child of that object.  If no parent handle is
provided then a new figure and the necessary children will be constructed
using the default values from the root figure.
</p>
<p>A third boolean argument <var>hilev</var> can be passed to specify whether the
function should preserve listeners/callbacks, e.g., for legends or
hggroups.  The default is false.
</p>
<p><strong>See also:</strong> <a href="#XREFhdl2struct">hdl2struct</a>, <a href="Printing-and-Saving-Plots.html#XREFhgload">hgload</a>, <a href="Searching-Properties.html#XREFfindobj">findobj</a>.
</p></dd></dl>


<a name="XREFcopyobj"></a><dl>
<dt><a name="index-copyobj"></a>Function File: <em><var>hnew</var> =</em> <strong>copyobj</strong> <em>(<var>horig</var>)</em></dt>
<dt><a name="index-copyobj-1"></a>Function File: <em><var>hnew</var> =</em> <strong>copyobj</strong> <em>(<var>horig</var>, <var>hparent</var>)</em></dt>
<dd><p>Construct a copy of the graphic object associated with handle <var>horig</var>
and return a handle <var>hnew</var> to the new object.
</p>
<p>If a parent handle <var>hparent</var> (root, figure, axes, or hggroup) is
specified, the copied object will be created as a child of <var>hparent</var>.
</p>
<p><strong>See also:</strong> <a href="#XREFstruct2hdl">struct2hdl</a>, <a href="#XREFhdl2struct">hdl2struct</a>, <a href="Searching-Properties.html#XREFfindobj">findobj</a>.
</p></dd></dl>


<hr>
<div class="header">
<p>
Next: <a href="Graphics-Object-Properties.html#Graphics-Object-Properties" accesskey="n" rel="next">Graphics Object Properties</a>, Previous: <a href="Introduction-to-Graphics-Structures.html#Introduction-to-Graphics-Structures" accesskey="p" rel="prev">Introduction to Graphics Structures</a>, Up: <a href="Graphics-Data-Structures.html#Graphics-Data-Structures" accesskey="u" rel="up">Graphics Data Structures</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
</div>



</body>
</html>