Graphical input from a mouse or cursor.
[X,Y] = GINPUT(N) gets N points from the current axes and returns
the X- and Y-coordinates in length N vectors X and Y. The cursor
can be positioned using a mouse (or by using the Arrow Keys on some
systems). Data points are entered by pressing a mouse button
or any key on the keyboard. A carriage return terminates the
input before N points are entered.
[X,Y] = GINPUT gathers an unlimited number of points until the
return key is pressed.
[X,Y,BUTTON] = GINPUT(N) returns a third result, BUTTON, that
contains a vector of integers specifying which mouse button was
used (1,2,3 from left) or ASCII numbers if a key on the keyboard