MATLAB: How to change axis of a matix

Question

my matrix is M(x,y,z) where:

x=1:90
y=1:3:120
z=1:40

and

c=y./z

and I need to convert M into N(x,c).

Any ideas?

Answer 1

load('testdata.mat');
Ufun = @(X,Y,Z) X;
Vfun = @(X,Y,Z) Y./(Z+200);
[X,Y,Z] = ndgrid(x,y,z);
U = Ufun(X,Y,Z);
V = Vfun(X,Y,Z);
U = U(:);
V = V(:);
[umin,umax] = bounds(U);
nu = 21;
u = linspace(umin,umax,nu);
[vmin,vmax] = bounds(V);
nv = 21;
v = linspace(vmin,vmax,nv);
[~,~,I] = histcounts(U,u);
[~,~,J] = histcounts(V,v);
N = accumarray([J I], M(:), [nu nv]-1, @mean, NaN);
midfun = @(x) 0.5*(x(1:end-1)+x(2:end));
u = midfun(u);
v = midfun(v);
surf(u,v,N);
xlabel('u (=x)');
ylabel('v (=y/(200+z)');