Question

I have a mesh grid defined as

[X, Y, Z] = meshgrid(-100:100, -100:100, 25); % z will have more values later

and two shapes (ovals, in this case):

x_offset_1 = 40;
x_offset_2 = -x_offset_1;
o1 = ((X-x_offset_1).^2./(2*Z).^2+Y.^2./Z.^2 <= 1);
o2 = ((X-x_offset_2).^2./(2*Z).^2+Y.^2./Z.^2 <= 1);

Now, I want to find all points that are nonzero in either oval. I tried

union = o1+o2;

but since I simply add them, the overlapping region will have a value of 2 instead of the desired 1.

How can I set all nonzero entries in the matrix to 1, regardless of their previous value?

(I tried normalized_union = union./union;, but then I end up with NaN in all 0 elements because I’m dividing by zero…)

Answer 1

Simplest solution: A=A~=0;, where A is your matrix.

This just performs a logical operation that checks if each element is zero. So it returns 1 if the element is non-zero and 0 if it is zero.