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

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1answer
40 views

Plotting a dataset and its fit dynamically

I have the dataset ...
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0answers
491 views

Interpolating function as a model in Mathematica's procedures for fitting

Is it possible to use interpolating function with parameters as a model for NonLinearModelFit (and other integrated methods for fitting)? Similar question was ...
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0answers
184 views

FindFit for dimension reduction?

Given an n-dimensional function, can I use FindFit to produce an approximate (n-k)-dimensional function? Here is a simplified illustration of what I am trying to do....
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0answers
28 views

Priority on Fitparameters

I try to fit a function using the FindFit expression. My problem is that ZL has to be ...
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0answers
57 views

Solve equations involving summation expressions in Mathematica

I am trying to solve the simple linear regression equation analytically in Mathematica (not using builtin functions). I managed to calculate the gradient as follows f is loss function using RSS and ...
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0answers
29 views

data fit using second order PDE

I'm trying to find the parameter for second order PDE using data. i don't know what is the error of that, ...
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0answers
57 views

Numerical fitting trajectory to model that has NDSolve

I have a model which describes the motion of an object on a plane. ...
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0answers
31 views

Use “FindFit” for Multi-variable Polynomial Fit

I'm interested in defining three input vectors: $L=\{L_{1}, \ldots, L_{N} \}$ $W=\{W_{1}, \ldots, W_{N} \}$ $Q=\{Q_{1}, \ldots, Q_{N} \}$ and I'm hoping to be able to input a number for each of ...
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0answers
36 views

Is it possible to get the error estimates of predicted values computed by FindMinimum using the Levenberg Marquardt method?

I use the LevenbergMarquardt method of the FindMinimum function to minimize a residual function (mathematical-optimization). This residual function is computed from experimental data and the solution ...
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0answers
46 views

How to fit a plot with error bar as weight?

I try to fit a line which can fit through the points considering the error weight of each coordinate. Is it possible to do in Mathematica? I can only find Fit function which did not do what I really ...
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0answers
48 views

Fitting 6 differential equations to 6 sets of data

I am using the newest Mathematica and I am trying to fit a set of 6 linear differential equations to a set of experimental data for each of the six variables. I am a baby beginner at this and could ...
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0answers
44 views

Finding error in an exponential fit

I'm a beginner with Mathematica and I'm trying to find the error in 'A' from the following fit: -A I0 E^(-Y A) The code I've used to plot the fit is the ...
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0answers
65 views

Exact meaning of `VarianceEstimatorFunction`

After reading the documentation, it's still unclear for me what VarianceEstimatorFunction does when fed with two arguments: ...
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0answers
44 views

fit multiple dataset with a single ODE to extract parameters

I found my problem very similar to the one discussed in here. But I'm having difficulties to fit multiple dataset (with varied temperatures) to a single ODE. The hurdle for me now is since the rate ...
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0answers
80 views

Maximum Likelihood Estimation of Gamma-distribution Scale parameter

I have the following tasks: Generate random sample with given parameters shape = 2, scale = 0.001 and shape = 2, scale = 1/1200 for the right censored sample; Using Maximum Likelihood Method ...
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0answers
34 views

How to calculate a required definition only once for each iteration of NonlinearModelFit

This is my first post here. I've been using Mathematica for about 4 years now to analyze data, but am still very new and have no background in formal programming. This is the first question I couldn't ...
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0answers
48 views

Incorporating sophisticated constraints on the approximating function into NMinimize

Following the approach as given in the answer of Belisarius here I just wonder how one could incorporate some more sophisticated requirements on the approximating function. Suppose the approximating ...
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0answers
32 views

EstimatedBackground function on Mathematica 9

Is there a way to replicate the EstimatedBackground function on Mathematica 9?
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0answers
61 views

Using the results of FindPeak in FindFit

Using FindPeak on some datapoints, I have found the positions and values of likely Gaussian peaks which form the data. The format is ...
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0answers
66 views

FindFit giving many errors when given model produced by ParametricNDSolveValue

I am trying to use FindFit to determine 7 parameters using 7 differential equations based on data imported from Excel. A sample of the data is: ...
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0answers
74 views

Modify measured values to improve NonlinearModelFit results

Problem: Measured data points have a random distribution of DC offsets (either +/- 0.65 mV), that came from an incorrect setting on the 24-bit ADC we were using. Essentially for each measured voltage ...
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0answers
95 views

How to make a twice-differentiable function that approximates some data?

I have some time series data that I would like to approximate with a twice-differentiable function. Each time series has ~10,000 datapoints, so I definitely do not want a function that passes through ...
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0answers
39 views

How to use FindFit to find the parameter in Laplace space(numerically inverting Laplace transforms)

I am trying to find the parameter in Laplace space, and a very simple example is shown below: I have known the solution $y_{laplace}$ in the laplace space is $a/s^2$, and I also have some discrete ...
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0answers
213 views

Decompose Point-Spread Function into Seidel Aberration/Zernike Polynomials

I have measured the point spread function (PSF of a microscope) and I want to quantify it. For that purpose I want to fit my PSF data to the primary Seidel optical aberrations (or Zernike Polynomials, ...
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0answers
111 views

Fit a complicated function to a constant with NonlinearModelFit

I wish to fit a complicated parametric function (logder, with lambda parameters) to a constant (L) in order to minimize its dependence with the variable k in a given interval. To do that, I use a ...
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0answers
56 views

NonlinearModelFit not hunting for good values

I have the following data which come from complex values but I have turned them into a 3D list ...
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0answers
512 views

Extracting parameters from a fitted function

Let's say I have written a function which performs convolution and returns value calculated for the time, t. ...
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0answers
141 views

How to perform a distribution fit test to censored data

With following code I will get an error: ...
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0answers
101 views

Fitting data set with series expansion

I have a function given in a form of a list: ScalarField={{$\epsilon$,$y_1$},..{1,$y_{3000}$}} It is defined in the range $(\epsilon,1)$ (spacing between grid points is homogeneous), where $\...
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0answers
226 views

Using FindFit for step functions

Having used FindFit like so: ...
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0answers
127 views

Smoothing a function

NDsolve gives me a solution to a certain NL PDE. I want to evaluate the rate of exponential decay of the maxima of the solutions in time. So, I plot ...