After taking measurements I get a two-dimensinal matrix of measurement values where the position in the Matrix corresponds to the position the measuerment was taken at. From this data I want to get the minimal and maximal -3 dB (Signal at 1/2 strenght) diameter, where 0 dB is the point in the Matrix with the maximal value.
Getting the curve through all points at -3 dB can be done with this:
[M, c] = contour(Matrix, [maxVal/2, maxVal/2]);
But I do not know how to continue with this. I thought about "slicing" the matrix with a number of lines through the maxVal-point at different angles and to then find the distance of the two points at the intersections of the line and the curve. But this does not seem to be a nice solution.
Is there an easier or more elegant solution?
The -3 dB-curves are usually ellipses.