How do I extract data from polyshape figures

I know how to extract data from a regular figure, e.g., open('example.fig'); a = get(gca,'Children'); xdata = get(a, 'XData'); ydata = get(a, 'YData');

However, I'm stuck when it comes to figures that were created with polyshapes.

Answer 1

[jonas]

If you are looking to extract the polyshape, then it's stored in the polygon object's shape property.

So for example

% Plot polygon
p=polyshape([0 1 1 0],[0 0 1 1])
plot(p)

% Extract
ax=gca;
ax.Children.Shape

[Steven Lord]

I would use findobj instead of assuming that gca still refers to the axes in which the polyshape was plotted and that the axes only has one child. [For purposes of this example I do make the assumption that only one polygon was plotted, so if we find one it's the right one, but you could test that poly1 isscalar and handle the cases where it is not appropriately.]

>> p=polyshape([0 1 1 0],[0 0 1 1]);
>> plot(p);

>> poly1 = findobj(groot, 'type', 'polygon');
>> p2 = poly1.Shape;
>> isequal(p, p2)

ans =
  logical
   1

As written this code will find all polygon objects you've plotted because it looks for everything under groot. You can change that first input to search in just a particular figure or axes.