How to make a contour plot with incomplete z data?

I have a collection of intersection points of a square plane. Each intersection point has an intensity associated with it (doing light ray tracing). I need the intensity to be the elevation of the contour plot, and the points to be the x and y respectively. Areas not intersected by any rays need to have an elevation of zero. I have a vector that has x values of intersection, a vector that has y values of intersection, and a vector that has intensities. I'm not sure how to make a contour plot using this information. Using the contourf function with those vectors as an input says that Z must be at least a 2x2 matrix, and I don't know how to form this matrix when basically any point that isn't included needs to have an elevation of 0. Any guidance is appreciated!

[Chris]

This is a duplicate.

https://www.mathworks.com/matlabcentral/answers/1580054-how-to-make-a-contour-plot-with-incomplete-z-data?s_tid=srchtitle

Answer 1

[Sulaymon Eshkabilov]

As I understood your question correctly, you'd need to employ something like this one to get controurf(Z) from the values of X and Y.

X = randi(255, 25, 1);
Y = randi(255, 25, 1);
XY = [X.*(X>175), Y.*(Y>175)];
Z = XY;
contourf(Z)