One approach is to use meshgrid to create matrices out of ‘x’ and ‘y’, then plot all of them as vectors, using the (:) subscript notation to force them all to become column vectors:
N = 5;
M = 8;
x = 1:N;
y = 1:M;
[X,Y] = meshgrid(x,y);
z = randn(N,M) + 1j*randn(N,M);
figure
scatter3(X(:), Y(:), abs(z(:)), 25, abs(z(:)), 'filled', 'Marker','p')
colormap(jet(numel(z)))
colorbar
Experiment to get the result you want.
