True for graphics object handles
ishghandle(h) returns an array that contains 1's where the elements of
h are handles to existing graphics objects and 0's where they are
not. Differs from
ishandle in that Simulink® objects handles return false.
Create a plot. Test if the output
p is a valid graphics object handle.
x = 1:10; y = 1:10; p = plot(x,y);
ans = logical 1