[Gnuplot-info] Gnuplot - Problem with exponential fit

[f.hasenbeck <f.h...@fz...>]

  Hi!

I have a problem with an exponential fit. My script looks like this:


n_0 = 3.0e+12
lambda = 0.7
f(x) = n_0*exp((-x)/lambda)

fit f(x) '../95896_029/c_001/run/rad_profile_exp_decay_torzone_1.txt' u
($4-217):2 via n_0, lambda


I am using the two fitting parameters n_0 and lambda, but only lambda is
varied by GNUPLOT, no matter which starting value I use vor n_0. This
seems strange since a variation of n_0 also should be able to provide
better fitting results. Is there a solution to this problem so that
GNUPLOT also varies n_0?

Thank you very much for your help!

Felix Hasenbeck

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