MATLAB: How to create a 3 dimensional response surface plot from X Y Z points

Question

Hi all,

I am struggling a bit here, and hope somebody could help. I have a set of X Y and Z points and Z is not found by any function of X and Y. In other words, I have independent X Y and Z values and these values are;

X Y Z

288 2.79 7.55

318 4.64 14.28

127 2.31 8.31

132 7.16 17.27

264 2.31 4.32

200 2.60 6.74

268 3.06 15.12

I need to create a response surface plot (contour plot) from these values. I would be so glad and thankful if somebody could help with with that. I am sorry if question is not very clear. If not, I can ask in detail. In sort, I have eight X Y Z independent data and want to create a response surface.

Best Regards,

Ferdi

Answer 1

How about using an interpolation? The following is a simple example:

% Apply cubic interpolation 
[xGrid,yGrid] = meshgrid(linspace(min(X),max(X)),linspace(min(Y),max(Y)));
zGrid = griddata(X(:),Y(:),Z(:),xGrid(:),yGrid(:),'cubic');
zGrid = reshape(zGrid,size(xGrid));
% Visualize the result
figure
contour(xGrid,yGrid,zGrid,'ShowText','on')
hold on
scatter(X,Y,'ro')
grid on
colorbar