15.1.3 Plot Annotations

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.

Function File: title (title)

Function File: title (title, p1, v1, …)

Create a title object and return a handle to it.

Function File: legend (st1, st2, …)

Function File: legend (st1, st2, …, "location", pos)

Function File: legend (matstr)

Function File: legend (matstr, "location", pos)

Function File: legend (cell)

Function File: legend (cell, "location", pos)

Function File: legend ('func')

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. 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:

	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

Some specific functions are directly available using func:

"show"

Show legends from the plot

"hide"

"off"

Hide legends from the plot

"boxon"

Draw a box around legends

"boxoff"

Withdraw the box around legends

"left"

Text is to the left of the keys

"right"

Text is to the right of the keys

Function File: h = text (x, y, label)

Function File: h = text (x, y, z, label)

Function File: h = text (x, y, label, p1, v1, …)

Function File: h = text (x, y, z, label, p1, v1, …)

Create a text object with text label at position x, y, z on the current axes. Property-value pairs following label may be used to specify the appearance of the text.

See Text Properties for the properties that you can set.

Function File: xlabel (string)

Function File: ylabel (string)

Function File: zlabel (string)

Function File: xlabel (h, string)

Specify x, y, and z axis labels for the current figure. If h is specified then label the axis defined by h.

See also: plot, semilogx, semilogy, loglog, polar, mesh, contour, bar, stairs, title.

Function File: clabel (c, h)

Function File: clabel (c, h, v)

Function File: clabel (c, h, "manual")

Function File: clabel (c)

Function File: clabel (c, h)

Function File: clabel (…, prop, val, …)

Function File: h = clabel (…)

Adds labels to the contours of a contour plot. The contour plot is specified by the contour matrix c and optionally the contourgroup object h that are returned by contour, contourf and contour3. The contour labels are rotated and placed in the contour itself.

By default, all contours are labelled. 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. Additionally, the property "LabelSpacing" is available allowing the spacing between labels on a contour (in points) to be specified. The default is 144 points, or 2 inches.

The returned value h is the set of text object that represent the contour labels. 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);

See also: contour, contourf, contour3, meshc, surfc, text.

Function File: box (arg)

Function File: box (h, …)

Control the display of a border around the plot. The argument may be either "on" or "off". If it is omitted, the current box state is toggled.

See also: grid.

Function File: grid (arg)

Function File: grid ("minor", arg2)

Function File: grid (hax, …)

Force the display of a grid on the plot. The argument may be either "on", or "off". If it is omitted, the current grid state is toggled.

If arg is "minor" then the minor grid is toggled. When using a minor grid a second argument arg2 is allowed, which can be either "on" or "off" to explicitly set the state of the minor grid.

If the first argument is an axis handle, hax, operate on the specified axis object.

See also: plot.

Function File: colorbar (s)

Function File: colorbar ("peer", h, …)

Adds a colorbar to the current axes. Valid values for s 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.

"Off", "None"

Remove any existing colorbar from the plot.

If the argument "peer" is given, then the following argument is treated as the axes handle on which to add the colorbar.