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Hi All

I am just starting to use ES to simulate my EPR spectra. There is a question that may sound stupid but is in need of your help. Once I complete the fitting, I don't how to proceed to output the simuated spectrum. I tried the following code but it did not work and what I recieved is the raw experimental data.

= esfit('pepper', spc, Sys, Vary, Exp, SimOpt, FitOpt);
data = [B(:) spc(:)];
save('simdata.txt','data','-ascii');

Can anyone advise me how to sort out this problem. Many thanks.

Tony

Unlike EasySpin's simulation functions, esfit does not return the x-axis. You can construct it yourself very easily using your settings in Exp

Thanks Stefan
I did change the code as you suggested. A new error pops up,

The following error occurred converting from double to struct:
Error using struct
Conversion to struct from double is not possible.

Error in simcode (line 41)
data = [B(:) spc(:)];

what i want to do is to save the simulated spectum into a txt file by using the following codes,
data = [B(:) spc(:)];
save('simdata.txt','data','-ascii');

Can you further advise me what problem this is. Thank you.

Tony

From esfit you have two potential outputs.
If you only have one output argument you'll get your fit paramters such as: If you provide two outputs the first one best fit parameters and the second is the best fit spectrum so you'd need to do:
*edited to address errors.

thanks for your reply. An error in data = [B(:) spc(:)] remains.
Below is the code i used. Please advise me how to improve. Thank you.

clear

% below is a standard fitting code
[B,spc] = eprload('La.par')
Sys0.S = 1/2;
Sys0.Nucs = '139La, 139La, 139La';

Exp.mwFreq = 9.386; % GHz
Exp.Range = [170 470]; % in mT Field range use for sims and esfit
nPoints = numel(spc); % number of points in spectral data vector
B = linspace(Exp.Range(1),Exp.Range(2),nPoints); % field axis


% Now we set up the least-squares fitting.
% First comes a starting set of parameters (which we
% obtain by copying the spin system from the simulation
% and changing a few values)
Sys0.g = [2.002 2.002 2.002];
Sys0.A = [60 140 170]; % MHz nuclei added using a set of fields 90 150 190
Sys0.lwpp = 1.2; % mT 1.802 [1.8020 2.1593 2.2020 90 200 220]

% Next, we specify which parameter we want to be fitted
% and by how much the fitting algorithm can vary it approximately.
Vary.g = [0.05 0.05 0.05];
Vary.A = [10 20 20];
SimOpt.Method = 'perturb';

% Calling the fitting function
FitOpt.Method = 'simplex int'; % simplex algorithm, integrals of spectra
[spc, fitparams] = esfit('pepper',spc,Sys0,Vary,Exp,SimOpt,FitOpt);
data = [B(:) spc(:)];
save('myfile.txt','data', '-ascii');
plot(B, spc);

Oops that was a bunch of wrong stuff on my part, if you glance at the output from esfit you'll see that one of them is a structure the other is just a vector. I flipped around what the outputs actually are, the first output are the best fit parameters while the second is the best fit spectrum.

I edited the above post to fix my error.