Next: Multiple Plots on One Page, Previous: Three-Dimensional Plots, Up: High-Level Plotting [Contents][Index]
You can add titles, axis labels, legends, and arbitrary text to an existing plot. For example:
x = -10:0.1:10; plot (x, sin (x)); title ("sin(x) for x = -10:0.1:10"); xlabel ("x"); ylabel ("sin (x)"); text (pi, 0.7, "arbitrary text"); legend ("sin (x)");
The functions grid
and box
may also be used to add grid
and border lines to the plot. By default, the grid is off and the
border lines are on.
Finally, arrows, text and rectangular or elliptic boxes can be added to
highlight parts of a plot using the annotation
function. Those objects
are drawn in an invisible axes, on top of every other axes.
Specify the string used as a title for the current axis.
An optional list of property/value pairs can be used to change the appearance of the created title text object.
If the first argument hax is an axes handle, then plot into this axis,
rather than the current axes returned by gca
.
The optional return value h is a graphics handle to the created text object.
Display a legend for the current axes using the specified strings as labels.
Legend entries may be specified as individual character string arguments, a character array, or a cell array of character strings.
If the first argument hax is an axes handle, then plot into this axis,
rather than the current axes returned by gca
. If the handles,
hobjs, are not specified then the legend’s strings will be associated
with the axes’ descendants. legend
works on line graphs,
bar graphs, etc. A plot must exist before legend is called.
The optional parameter pos specifies the location of the legend as follows:
pos | location of the legend | |
---|---|---|
north | center top | |
south | center bottom | |
east | right center | |
west | left center | |
northeast | right top (default) | |
northwest | left top | |
southeast | right bottom | |
southwest | left bottom | |
outside | can be appended to any location string |
The optional parameter orient determines if the key elements
are placed vertically or horizontally. The allowed values are
"vertical"
(default) or "horizontal"
.
The following customizations are available using option:
"show"
Show legend on the plot
"hide"
Hide legend on the plot
"toggle"
Toggles between "hide"
and "show"
"boxon"
Show a box around legend (default)
"boxoff"
Hide the box around legend
"right"
Place label text to the right of the keys (default)
"left"
Place label text to the left of the keys
"off"
Delete the legend object
The optional output values are
The graphics handle of the legend object.
Graphics handles to the text and line objects which make up the legend.
Graphics handles to the plot objects which were used in making the legend.
A cell array of strings of the labels in the legend.
The legend label text is either provided in the call to legend
or
is taken from the DisplayName property of graphics objects. If no
labels or DisplayNames are available, then the label text is simply
"data1"
, "data2"
, …, "dataN"
.
Implementation Note: A legend is implemented as an additional axes object
of the current figure with the "tag"
set to "legend"
.
Properties of the legend object may be manipulated directly by using
set
.
Create a text object with text string at position x, y, (z) on the current axes.
Multiple locations can be specified if x, y, (z) are vectors. Multiple strings can be specified with a character matrix or a cell array of strings.
Optional property/value pairs may be used to control the appearance of the text.
The optional return value h is a vector of graphics handles to the created text objects.
See Text Properties for the properties that you can set.
Specify the string used to label the x-axis of the current axis.
An optional list of property/value pairs can be used to change the properties of the created text label.
If the first argument hax is an axes handle, then operate on
this axis rather than the current axes returned by gca
.
The optional return value h is a graphics handle to the created text object.
Add labels to the contours of a contour plot.
The contour levels are specified by the contour matrix c which is
returned by contour
, contourc
, contourf
, and
contour3
. Contour labels are rotated to match the local line
orientation and centered on the line. The position of labels along the
contour line is chosen randomly.
If the argument h is a handle to a contour group object, then label
this plot rather than the one in the current axes returned by gca
.
By default, all contours are labeled. However, the contours to label can be
specified by the vector v. If the "manual"
argument is
given then the contours to label can be selected with the mouse.
Additional property/value pairs that are valid properties of text objects
can be given and are passed to the underlying text objects. Moreover,
the contour group property "LabelSpacing"
is available which
determines the spacing between labels on a contour to be specified. The
default is 144 points, or 2 inches.
The optional return value h is a vector of graphics handles to
the text objects representing each label.
The "userdata"
property of the text objects contains the numerical
value of the contour label.
An example of the use of clabel
is
[c, h] = contour (peaks (), -4 : 6); clabel (c, h, -4:2:6, "fontsize", 12);
Control display of the axis border.
The argument may be either "on"
or "off"
. If it is
omitted, the current box state is toggled.
If the first argument hax is an axes handle, then operate on
this axis rather than the current axes returned by gca
.
Control the display of plot grid lines.
The function state input may be either "on"
or "off"
.
If it is omitted, the current grid state is toggled.
When the first argument is "minor"
all subsequent commands
modify the minor grid rather than the major grid.
If the first argument hax is an axes handle, then operate on
this axis rather than the current axes returned by gca
.
To control the grid lines for an individual axis use the set
function. For example:
set (gca, "ygrid", "on");
Add a colorbar to the current axes.
A colorbar displays the current colormap along with numerical rulings so that the color scale can be interpreted.
The optional input loc determines the location of the colorbar. Valid values for loc are
"EastOutside"
Place the colorbar outside the plot to the right. This is the default.
"East"
Place the colorbar inside the plot to the right.
"WestOutside"
Place the colorbar outside the plot to the left.
"West"
Place the colorbar inside the plot to the left.
"NorthOutside"
Place the colorbar above the plot.
"North"
Place the colorbar at the top of the plot.
"SouthOutside"
Place the colorbar under the plot.
"South"
Place the colorbar at the bottom of the plot.
To remove a colorbar from a plot use any one of the following keywords for
the delete_option: "delete"
, "hide"
, "off"
.
If the argument "peer"
is given, then the following argument is
treated as the axes handle in which to add the colorbar. Alternatively,
If the first argument hax is an axes handle, then the colorbar is
added to this axis, rather than the current axes returned by gca
.
If the first argument hcb is a handle to a colorbar object, then operate on this colorbar directly.
Additional property/value pairs are passed directly to the underlying axes object.
The optional return value h is a graphics handle to the created colorbar object.
Implementation Note: A colorbar is created as an additional axes to the
current figure with the "tag"
property set to "colorbar"
.
The created axes object has the extra property "location"
which
controls the positioning of the colorbar.
See also: colormap.
Draw annotations to emphasize parts of a figure.
You may build a default annotation specifying only the type
type of the annotation. Otherwise you can set the position of
the annotation using either x and y coordinates for
line-based annotations or a position vector pos for others.
In any case, coordinates are interpreted using the "units"
property of the annotation objects: the default is
"normalized"
, which means the lower left hand corner of the
figure has coordinates ‘[0 0]’ and the upper right hand corner
‘[1 1]’.
The figure on which the annotations should be drawn may be specified by providing its graphics handle hf before any other argument. Otherwise annotations are drawn on the current figure.
Further arguments can be provided in the form of
prop/val pairs to customize the annotation appearance
and the units in which coordinates are interpreted. The annotation
can also be customized afterward using its graphics handle
h and set
function.
All annotation objects share two properties:
"units"
: the units in which coordinates are interpreted.
Its value may be one of "centimeters"
|
"characters"
| "inches"
| "{normalized}"
| "pixels"
| "points"
.
"position"
: a four elements vector [x0 y0 width height]
specifying the coordinates (x0,y0) of the origin of the annotation
object, its width and its height. The width and height may be
negative, depending on the orientation of the object.
Valid annotation types and their specific properties are described below:
"line"
Constructs a line. x and y must be two elements vectors specifying the x and y coordinates of the two ends of the line.
The line can be customized using "linewidth"
,
"linestyle"
and "color"
properties the same way
as with line
objects.
"arrow"
Construct an arrow. The second point in vectors x and y specifies the arrowhead coordinates.
Besides line properties, the arrowhead can be customized using
"headlength"
, "headwidth"
and "headstyle"
properties. Supported values for "headstyle"
property are:
["diamond"
| "ellipse"
| "plain"
|
"rectangle"
| "vback1"
| "{vback2}"
|
"vback3"
]
"doublearrow"
Construct a double arrow. Vectors x and y specify the arrowheads coordinates.
The line and the arrowhead can be customized as for arrow
annotations but some property names are duplicated:
"head1length"
/"head2length"
,
"head1width"
/"head2width"
, etc. The index 1 marks
the properties of the arrowhead at the first point in x and
y coordinates.
"textarrow"
Construct an arrow with a text label at the opposite of the arrowhead.
The line and the arrowhead can be customized as for arrow
annotations, and the text can be customized using the same
properties as text
graphics objects. Note however
that some text property names are prefixed with "text" to
distinguish arrow and text properties:
"textbackgroundcolor"
, "textcolor"
,
"textedgecolor"
, "textlinewidth"
,
"textmargin"
, "textrotation"
.
"textbox"
Construct a box with a text inside. pos specifies the
"position"
property of the annotation.
You may use "backgroundcolor"
, "edgecolor"
,
"linestyle"
, "linewidth"
properties to customize
the box background color and edges appearance. A limited set of
text
objects properties is also available: besides
"font…"
properties, you may also use
"horizontalalignment"
and "verticalalignment"
to
move the text inside the box.
Finally the "fitboxtotext"
property controls the actual
extent of the box. If "on"
(the default) the
box limits are fitted to the text extent.
"rectangle"
Construct a rectangle. pos specifies the
"position"
property of the annotation.
You may use "facecolor"
, "color"
,
"linestyle"
and "linewidth"
properties to customize
the rectangle background color and edges appearance.
"ellipse"
Construct an ellipse. pos specifies the
"position"
property of the annotation.
See "rectangle"
annotations for customization.
Next: Multiple Plots on One Page, Previous: Three-Dimensional Plots, Up: High-Level Plotting [Contents][Index]