Some newbie in pepper

[anubis_by_itself]

Hello
I'm using esfit pepper to fit some Mn spectrum.
When I'm using monte-carlo or other global methods it keeps informing me with this:
WARNING: No resonance fields at 9.8 GHz between 310.345 and 398.052 mT.
Check field range and spectrometer frequency.
Warning: Rank deficient, rank = 1, tol = 2.057952e-11.

In rescale
In esfit
In esfit_montecarlo
In esfit

Script in the attachment
Could someone help me to fit this correctly? I just know it is X-band spectrum of Mn ethalone

[imoseley94]

Without the DSC file along with the DTA I am not sure I can confirm your issue. I would try changing the Exp.Range to what ever values you want to use "Exp.Range = [0 500]; % in mT " As you may be having some confusion since you are using a B/10 conversion factor as well. Hope you figure it out.

[anubis_by_itself]

Here it is. Could you please help me out with it?

[Matt Krzyaniak]

The specific error you've encountered likely comes from the range you've provided with vary being overly large(specifically vary.g). As a result, some of the parameter sets generated from monte-carlo end up being out of the field range you've specified.

In general though, I would say its good practice to adjust your initial parameters to get a reasonably good fit, this also gives you a better idea on the range to vary, then use esfit either with simplex or or levmar to nail down the fit. So do something like this:

Code: Select all

clear, clc, clf
[B,spc,par] = eprload('3Mn_etalon_MX_120_17_10_13.DTA');
B = B/10;
spc=spc/max(spc);
plot(B,spc);

Mn.S = 1/2;            %MHz
Mn.Nucs = '55Mn';
Mn.g = 2;
Mn.lwpp = 0.5;          

Mn.A = 240;             %MHz

Exp.mwFreq = par.MWFQ/10^9;
Exp.Range = [min(B) max(B)];
Exp.ModAmp = 0.5;        %mT
Exp.nPoints = length(B);

[b1,sim] = pepper(Mn,Exp);
sim = sim/max(sim);
plot(B,spc,b1,sim)

%%
Vary.g = 0.5;
Vary.lwpp = 0.3;
Vary.A = 50;

esfit(@pepper,spc,Mn,Vary,Exp);

I personally have not had very good luck using any of the minimization methods aside from simplex or levmar.