how to create a contour for a fittype object?

Hi,

i've fitted a surface for a scattered data using the following commands:

 load('full_data.mat')

 ft = fittype( 'poly11' );

 opts = fitoptions( 'Method', 'LowessFit' );

 opts.Normalize = 'on';

 opts.Robust = 'LAR';

 [fitresult, gof] = fit( [full_data(:,1), full_data(:,2)], full_data(:,3), ft, opts );

is it possible to plot the contours for this surface after i plotted the surface itself using the next command:

 plot(fitresult, [full_data(:,1), full_data(:,2)], full_data(:,3) );

thank you for your help.

Answer 1

[Mike Garrity]

One simple way is to get the data from the surface that the plot method creates.

h = plot(fitresult, [full_data(:,1), full_data(:,2)], full_data(:,3) );
s = findobj(h,'Type','surface');
figure
contour(s.XData,s.YData,s.ZData)

The "cleaner" option would be to use the feval method. You need to pass in the XData and YData. Something like this:

load franke
T = table(x,y,z);
f = fit([T.x, T.y],T.z,'linearinterp');
[x,y]=meshgrid(linspace(500,3500,40),linspace(0,1,40));
z=feval(f,x,y);
contour(x,y,z)

[Dany]

thank you Mike.