How to fit with non-function

Can you please help.
I want to fit (x,y) data points (with errors bars of delta_x and delta_y) with:
f(x) = par(0) + par(1) * F1 + par(2) * F2
where F1 and F2 are functions, but they are complex itnegral functions, so I don’t write them in root. But I do have the values of F1 and F2 for all experimental data points x. So my functions F1 and F2 are in fact a list of values.
Can you suggest how to fit in order to extract the parameters p(0), p(1) , p(2) and their error bars?

thanks!


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@couet can you please help here?

Oksana.

You will need you make you own fitting function and access the data for F1 and F2 in it.

Thanks!
Do you maybe know a link to such an example? I am still unsure how to make the function and the fit.

May be @moneta has one.