obtain parameter from Curve Fitting toolbox

Hi,

I just bought the Curve Fitting toolbox. I am using the tpaps function :

http://www.mathworks.com/help/curvefit/tpaps.html

It contains 'R(f)', a roughness measure (as shown in the link above). Can you guys tell me how to output the value of this measure.

regards.

[David Sanchez]

Do you mean to send its value to the workspace?

[audley james]

yes my friend

Answer 1

[Matt J]

I think the best you're going to be able to do is a numerical approximation. Something like

    D1D1=@(z) diff(z,2,1);
    D2D2=@(z) diff(z,2,2);
    D1D2=@(z) diff(diff(z,1,1),2,1);
    sqIntegral=@(z) norm(z,'fro').^2;

    f=fnvals(tpaps(...),fineGrid);

    Rf = sqIntegral(D1D1(f)) + sqIntegral(D1D2(f)) +sqIntegral(D2D2(f));