Hello,
I would like to know which is the best tool for trying to organise my fitting procedure to experimental data Y(x,z). I have many sets of data Y(x,z) with errors, see example in figure where Y(x) is plotted for 3 values of z.
The number of x points changes with z, therefore the sets of data cannot be written as a matrix except if I do not fill with zero the missing points.
Then, I decide to make a separate fit for each z (even if in principle a surface fit to the whole set of data would be preferable).
I need to get the errors on the parameters p and I am using lsqcurve fit, and to test many different models, one example is the following:
Model_1= p(1) * (Ymodel conv Gaussian) + p(2)*Y1 +p(3) + p(4)*x
where:
Ymodel = f(T)*p(5)*p(6)^2 ./ ( (x.^2-p(6)^2).^2 + 4*(p(5) * x).^2 )
Ymodel is convoluted with a Gaussian with a given sigma
Y1: input set of data (same dimension of Y
where f(T) is a known function of the temperature T.
The goal is to obtain Ymodel. In all cases Ymodel must be convoluted with a Gaussian when fitting.
External data (Y1 in the example above) may be inclued, with an amplitude being a parameter of the fit (p(2) in the example above).
The model may have a varying number of parameter.
The models are defined in external function, for instance:
function [y,yM,y_noC,yD]=DHO2_R_BL(p,x,sig,f1,f2,Weight,Y1,T), where
p: fit parameters
sig=sigma of the Gaussian
f1, f2: parameters related to the convolution
Weight: 1/errors^2
The function above extracts some components of the model (model with and without convolution for example).
I then need to export parameters with an estimation of their errors (using nparci), and I also calculate the reduced chi square
My functions work (at least it looks like...), but given the high number of data and models, I would like to use some graphical interface to compare more efficiently the different models.
Ideally, I would be able to open two (or more) windows similar to the basic hand-made sketch here shown, in order to compare models and results.
What I am looking for is probably not very different from what produced by cftool, but with lsqcurvefit, conolution, external data....
I have no experience in GUI: could you give me some hints on the best way to tackle this problem?
Thank you in advance,
nando
