ginput function enables you to use the mouse or the arrow keys to select points to plot.
ginput returns the coordinates of the pointer's position; either the current position or the position when a mouse button or key is pressed. See the
ginput function for more information.
Example - Selecting Plotting Points from the Screen
This example illustrates the use of
ginput with the
spline function to create a curve by interpolating in two dimensions.
First, select a sequence of points,
[x,y], in the plane with
ginput. Then pass two, one-dimensional splines through the points, evaluating them with a spacing 1/10 of the original spacing.
axis([0 10 0 10])
% Initially, the list of points is empty.
xy = ;
n = 0;
% Loop, picking up the points.
disp('Left mouse button picks points.')
disp('Right mouse button picks last point.')
but = 1;
while but == 1
[xi,yi,but] = ginput(1);
n = n+1;
xy(:,n) = [xi;yi];
% Interpolate with a spline curve and finer spacing.
t = 1:n;
ts = 1: 0.1: n;
xys = spline(t,xy,ts);
% Plot the interpolated curve.
This plot shows some typical output.
|Displaying Contours in Polar Coordinates||Animation|