Contourf and Surf with repeated values

If I have a matrix (or a .mat file) like in screenshot, so with same ordered values, how can I do plot the third column as Z? The problem is that i can't give the first column as X and the second as Y.

Thank you!

Answer 1

[Fabio Freschi]

Suppose you have Nx divisions along the variable of the first column and Ny divisions along the variable of the second column. You must reshape the columns of your matrix according to Nx and Ny

clear variables, close all

Nx = 5;
Ny = 6;

% create your matrix with random inputs
x = linspace(0,1,Nx);
y = linspace(1,2,Ny);
[X0,Y0] = meshgrid(x,y);
Z0 = X0.^2-3*X0.*Y0;
M = [X0(:) Y0(:) Z0(:)];

% The engine you want starts here -----

% reshape the columns of the matrix
X = reshape(M(:,1),Ny,Nx);
Y = reshape(M(:,2),Ny,Nx);
Z = reshape(M(:,3),Ny,Nx);

% plot 
figure
surf(X,Y,Z);
view([1 1 1])

Hope it helps!