15.2.10 Interacting with Plots

The user can select points on a plot with the ginput function or select the position at which to place text on the plot with the gtext function using the mouse.

: [x, y, buttons] = ginput (n)

: [x, y, buttons] = ginput ()

Return the position and type of mouse button clicks and/or key strokes in the current figure window.

If n is defined, then capture n events before returning. When n is not defined ginput will loop until the return key RET is pressed.

The return values x, y are the coordinates where the mouse was clicked in the units of the current axes. The return value button is 1, 2, or 3 for the left, middle, or right button. If a key is pressed the ASCII value is returned in button.

Implementation Note: ginput is intenteded for 2-D plots. For 3-D plots see the currentpoint property of the current axes which can be transformed with knowledge of the current view into data units.

See also: gtext, waitforbuttonpress.

: waitforbuttonpress ()

: b = waitforbuttonpress ()

Wait for mouse click or key press over the current figure window.

The return value of b is 0 if a mouse button was pressed or 1 if a key was pressed.

See also: waitfor, ginput, kbhit.

: gtext (s)

: gtext ({s1, s2, …})

: gtext ({s1; s2; …})

: gtext (…, prop, val, …)

: h = gtext (…)

Place text on the current figure using the mouse.

The string argument s may be a character array or a cell array of strings. If s has more than one row, each row is used to create a separate text object after a mouse click. For example:

Place a single string after one mouse click

gtext ("I clicked here")

Place two strings after two mouse clicks

gtext ({"I clicked here"; "and there"})

Place two strings, each with two lines, after two mouse clicks

gtext ({"I clicked", "here"; "and", "there"})

Optional property/value pairs are passed directly to the underlying text objects.

The full list of text object properties is documented at Text Properties.

The optional return value h holds the graphics handle(s) to the created text object(s).

See also: ginput, text.

More sophisticated user interaction mechanisms can be obtained using the ui* family of functions, see UI Elements.