how to tell esfit to treat variables as equivalent?

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esalerno
Newbie
Posts: 2
Joined: Tue May 22, 2018 12:33 pm

how to tell esfit to treat variables as equivalent?

Post by esalerno »

Say I have a system of multiple spins. If these are modeled as equivalent (identical D, identical J between them), then a system can be given as that below. However for fitting with esfit, I do not see how to model them as equivalent. I.e. I would like each J parameter and each D parameter to be identical, and if these are the only parameters varied, then there should only be two variables to fit. However the preset script has six variables because I cannot figure out how to tell it that J=J12=J13=J23 and D=D1=D2=D3. Does anyone know how to tell the program to treat given parameters as identical?

Thanks

Code: Select all

spin=3/2;
Sys.S=[spin spin spin];

g=2.0023;
Sys.g = [g g g];

D=.5*29979.2458; %cm-1*[29979Mhz/cm-1]
Sys.D=[D D D]

J=-5*29979.2458; %cm-1*[29979Mhz/cm-1]
Sys.J=[J J J];

Exp.Temperature =5;
Sys.lwpp = 30;
Exp.mwFreq = 94;
Exp.Harmonic=0;

Sys0 = Sys;

% Specify which parameter we want to be fitted and by how much the
% fitting algorithm can vary it approximately.
%too many parameters for a good fitting
Vary.D = [10000 10000 10000];
Vary.J=[10000 10000 10000];

%spc is the data to be fitted
esfit('pepper',spc,Sys0,Vary,Exp);
thanasis
Local Expert
Posts: 242
Joined: Thu Jan 21, 2016 6:28 am
Location: Strasbourg

Re: how to tell esfit to treat variables as equivalent?

Post by thanasis »

Take a look at the use of custom functions at this thread: viewtopic.php?f=3&t=260

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