How to reproduce the example figure using lsqcurvefit

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Hi, I am trying to follow this example for non-linear curve fitting.
Looking at the section 'Splitting the Linear and Nonlinear Problems', I understood upto the point how to estimate two exponents lambda1 & 2 (line 51). However, I don't understand how to recover the estimate for 'c' to produce the 'Global fit' in the last figure in the following section.
More specifically, once I obtain the unknown lambdas, what should I do to obtain the unknown vector 'c' (in the function 'fitvector')? Which of the followings would be the right approach?
  1. c=A \ ydata
  2. c=A \ yEst, or
  3. Once obtained the estimates for lambda, I follow the full parameter estimation using the lambdas.
Thanks in advance for your help!

Answers (1)

Mathieu NOE
Mathieu NOE on 29 Sep 2021
well, if the question is only about how to use lsqcurvefit, my answer is not gotta help you because I'm using either fminsearch , or , much better and more robust to crude / bad initial guess : Fminspleas - File Exchange - MATLAB Central (
see the two examples attached if it helps you
all the best
Mathieu NOE
Mathieu NOE on 30 Sep 2021
Good idea , that would for sure interest me as well !

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