Using lsqcurvefit with constant parameters

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Hi, I am trying to use lsqcurvefit to fit data to an interference function that I created. The problem is that some of the parameters in the function should remain constant through the fitting process (ie. the wavelength of the laser does not change etc...). I have seen some other stabs at this but none that were thorough and actually worked when I ran them. Here is some of my code so you know what I am talking about:
initials = [Aref,Aprobe,w0,z,lambda,phi,x0,y0];
fitfunc = @(initials,x) InterferePhase1(initials,X2);
fitparams = lsqcurvefit(fitfunc,initials, X2 ,imageArray,[], []);
Ideally, I should be able to run this fit and have my initial values for lambda, x0, and y0 stay the same after lsqcurvefit runs.
Let me know if you need any additional information!
Thanks for all your help!

Accepted Answer

Matt J
Matt J on 24 Jul 2014
Edited: Matt J on 24 Jul 2014
initials = [Aref,Aprobe,w0,z,phi];
fitfunc = @(p,pdata) InterferePhase1([p(1:4),lambda,p(5),x0,y0],pdata);
fitparams = lsqcurvefit(fitfunc,initials, X2 ,imageArray);
  3 Comments
Matt J
Matt J on 24 Jul 2014
As you can see, though, my proposed fitfunc does pass 8 inputs to InterferePhase1 (that was the whole point). It embeds the 5 unknowns in an 8-vector which includes lambda, x0, and y0.
Chris
Chris on 25 Jul 2014
Ya I got it working and understand what you're doing now.
Thanks!

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