# Questions tagged [fitting]

Questions on the use of Mathematica to construct models for approximating empirical data.

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### Polynomial fitting to obtain the growth rate

We -- my friend -- had asked a question here, which was not completely related to Mathematica, however, in a hope that someone familiar with the topic could help. There are still some aspects which we ...
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### Two gaussian and linear curves

I wanted to fit two gaussian and linear curves, I tried to use nonlinear model fit, but I'm making somewhere a mistake. I know that one gaussian curve can be fitted as ...
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### How to add weights in fitting?

I have a set of data as: data = {{0, 0.046}, {40, 0.111}, {80, 0.291}, {120, 0.808}, {160, 1.742}, {200, 3.319}, {240, 5.017}, {280, 5.503}, {320, 5.897}} With ...
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### Fit: Experimental`NumericalFunction error when fitting a black-box function

Bug appearing in at least 12.0.0 and 12.3.1 I'm trying some multidimensional Chebyshev fits. First, define a wrapper to prevent premature symbolic evaluation (I don't want a power series result): <...
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### How to compute the unbiased fit variance considering the option "Weights" in "NonlinearModelFit"

I am doing a non linear model fit. I know how the fit variance is computed when I do NOT assign weights to the fit, for example: ...
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### How does Mathematica compute the covariance matrix using "MultiNonlinearModelFit"?

I am doing a simple multi-non linear fit. I get the covariance matrix. Does anyone know how Mathematica calculate this Matrix? I have found the computation when mathematica fit only one signal but ...
152 views

### nonlinearfitmodel, 3 parameters, max iterations = 10 million still not converging

I am trying to fit a set of data to the expression to population in the excited state in a Rabi oscillation problem. I am given # of states in ground and excited state, as well as detuning. I convert ...
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### FindFit problem in "Debye temperature" fitting

I am fitting the Debye temperature using FindFit, here is my code: ...
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### Any suggestions for improving my fitting?

This is not a completely Mathematica question, but I hope people who are familiar both with Mathematica and statistics could help me on this. I have a set of data as ...
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### Estimating parameters of a custom or constrained distribution

I am trying to estimate the parameters of a custom distribution (an approximation of the skew normal), but I can't get Mathematica to use DistributionFitTest, EstimatedDistribution, or ...
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### Fixed-Effects Model in Mathematica

I need to fit a model with fixed effects (country and time) to adress the multivariate relation between a dependent variable for 22 countries over 8 years and two independents with the same dimensions....
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### How to find appropriate surface fit?

I have 3d scan data (21 x 21 matrix), which is pretty rough, for which I need to find a smooth surface suitable for use outside Mathematica. Here's my data: ...
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### ComplexFit fits only part of fit parameters

I'm trying to fit experimental complex data with model: model = s/(1-I*t*fr) In the model I want to find real-valued parameters ...
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### Problem with ParameterFitting:""The function value...is not a list of real numbers..."

I'm trying to use the data: ...
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### How to fit an interference pattern with Interpolation and FindFit？

I have two sets of experimental data. LightSourceSpectrum2.txt InterferencePattern2.txt The first one is the light source spectrum data, which can become a function of f[ν] using Interpolation. (Note ...
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### Fitting data to a model

I am using the following code with the following data (which I called fn): data (fn) here: https://pastebin.com/WwANBjNx ...
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### Symbolic Regression

7+ years ago I posted a question here regarding symbolic regression in Mathematica. At that time there did not seem to be much built-in support for this. I'm interested in multi-input models of the ...
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### How to perform feature selection for machine learning applications?

Feature selection is fairly easy in e.g. Python's scikit-learn which sports a module and tutorials or MATLAB. Mathematica even touts that it uses feature selection ...
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### General::munfl - Precision lost in LinearModelFit

I am new to mathematica so I am confused regarding the loss of precision in LinearModelFit. In building a linear model with uora (1 or 2) and encodeSeverity (1,2 or 3) ...
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### How to find a fit for numerical data?

I would like to know how to fit a numerical data in two different ways. The first one is ...