# fitting's questions - English 1answer

991 fitting questions.

### Difficulty with FindFit with complex equation

0 answers, 36 views fitting
I want to fit the following equation for my experimental data. I used the following code but it does not give the answer. It gives only coordinates. Could you help me to solve this problem? ...

### 2 How to speed up multiple calls of NonlinearModelFit?

0 answers, 66 views performance-tuning fitting compile
I'm trying to do an insane amount of non-linear fits to large amounts of data sets. However, I found that the NonlinearModelFit is horribly slow. Here's the setup: ...

### NonlinearModelFit Method-> “LevenbergMarquardt”, “Newton”, “QuasiNewton”, etc?

0 answers, 41 views differential-equations fitting
Could someone please point me to a tutorial comparing and contrasting the advantages and disadvantages of the many methods to choose from when applying NonlinearModelFit?

### 2 How to correctly write a PDE solving module for NonlinearModelFit

2 answers, 66 views differential-equations fitting
I need to fit a model defined by numerical operations to test data and find the parameters of the PDE. The problem is that I have to NIntegrate the result obtained ...

### 5 Automatic Piecewise Approximation

1 answers, 97 views function-construction fitting
I would like to create the following function: It should approximate a function func[x] by piecewise polynomial interpolations, splitting the approximate function ...

### How to get more digits from Fit

Taking the example from the Mathematica documentation for Fit, consider the following ...

### fitting data with parameter plus distribution

1 answers, 34 views fitting
I have data that I would like to fit with Bessel function https://www.dropbox.com/s/7se9mb2epbietng/data.dat?dl=0 ...

### 3 How to apply assumptions to parameters for FindDistributionParameters?

2 answers, 76 views fitting distributions assumptions
Say I have data that I want to fit to a distribution while applying assumptions on one or more of the parameters. For example, for ParetoDistribution[k, α, μ]<...

### 3 Find good polynomial fit of square root

3 answers, 116 views fitting
I would like to find a good polynomial fit of the square root. I tried the following: ...

### -1 How to do two Lorentzian fit

1 answers, 64 views fitting
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### 1 Scaling and shifting in fitting of a LogNormal distribution from experimental data

1 answers, 31 views probability-or-statistics fitting
I have the following set of data: ...

### 1 How can I do a “linear” fit on a log log plot

2 answers, 46 views fitting logarithmic-scale
I have plotted some data with a log scale on both axes as shown in the image below. I want to be able to fit this data such that the fit appears as linear on this log-log plot but I haven't been able ...

### 2 How I can use FindFit to simultaneously fit two data sets to two equations having shared parameters? [duplicate]

0 answers, 25 views mathematical-optimization fitting
I think that FindFit package with the method Nminimize yields global minimum if initial values of adjustable parameters are ...

### -1 Non linear fitting of data with chi squared minimization method in mathematica

0 answers, 29 views fitting
I want to do a non-linear fitting of dataset by the chi squared minimization method in Mathematica. For an example I have a function f(x) = ax^3 + bx^2 + c dat={{0,0},{1,6},{2,19},{4.99},{10,1203}} ...

### 1 Standard error of a nonlinear fit

1 answers, 99 views probability-or-statistics fitting
I would like to better understand the process that Mathematica uses to determine the standard error when fitting with NonlinearModelFit. I have been reading this ...

### 1 Why isn't LinearModelFit behaving consistently at different levels of lists?

1 answers, 31 views fitting
I get the following results when I run the following regression on datass: ...

### 1 Curve fitting with variable number of Gaussian curve

2 answers, 121 views fitting
I have the data which appears like And I decided to use three Gaussian curves to fit it. (This code allows me to manipulate all three curves and put in best guesses for peak positions. Using these ...

### FindMinimum from DensityPlot

I need to find the values of x, y that correspond to the minimum value of the function (in this example it is -1.0, the black area). Code example: ...

### How do I fit experimental data by solving 3 coupled ODEs with adjustable parameters?

0 answers, 39 views equation-solving fitting
I want to fit experimental data by solving 3 coupled differential equations.The ODEs are rate equations modeling the dynamics of hot carriers in semiconductors after excitation. The function use fot ...

### 2 Fitting two equations to diferent parts of the same dataset

I have a system that transit between two different states. Each state output varies linearly with time, given by \$m t+c\$, where both lines intersect the \$x\$ axis in the same point. The output of this ...

### -1 Performing a nonlinear fit from data imported from a text file

1 answers, 46 views import fitting
I have a text file data that I imported and I want to fit it with a given equation. I tried to fit but it did not work and gives Here is my code: ...

### 50 How to perform a multi-peak fitting?

6 answers, 14.286 views fitting data peak-detection
I am wondering how to implement the multi-peak detecting and fitting in Mathematica. Following is an example of fitting the data using three peaks (such that the data ~ peak1 + peak2 + peak3). The ...

### Nonlinearfit with incomplete data

1 answers, 48 views fitting nonlinear
Suppose I have an ODE model and some incomplete time series datadata = {{0,1},{5,6.2},{14,18.4},{28,57.3},{90,105.2},{180,98}}My question, can I still use ...

### 2 Problem using NonlinearModelFit to 2 coupled differential equations

I am trying to find the parameters of a set of differential equations given experimental data. Before I tackled my set of 12 equations, I tried to solve a simpler and similar 2 equation system but ...

### 1 Fitting two overlapping sinusoids in a single set of data

0 answers, 63 views fitting data envelope
I have a set of datadata = Import["https://pastebin.com/raw/aqUwN2XR", "List"];that gives me a graph that looks as though it has two oscillating sinusoidal ...

### 4 How do I make LinearModelFit flexible to number of parameters using FromLetterNumber?

1 answers, 108 views fitting hold
I want to run LinearModelFit where the number of parameters is not fixed. For example, the following ...

### 2 How to improve my fit?

1 answers, 76 views fitting
I use the following code to fit some data given in a previous question of mine: ...

### -1 What is wrong with my fit?

1 answers, 88 views fitting error
I am trying to fit the following data:data = Import["https://pastebin.com/raw/gHdYLCbA", "Table"]I use the following code: ...

### Nonlinear model fit with Numerical integration

2 answers, 126 views numerical-integration fitting nonlinear
I'm having trouble writing a Nonlinear Model fit where the model is a numerical integral evaluated with NIntegrate. I have read other questions and answers about more or less the same problem, but for ...

### 1 Improving nonlinear model fit (piecewise function)

1 answers, 42 views fitting nonlinear
I have a piecewise relatively simple function, and I'm looking for three parameters. Here's an MWE: ...

### NonlinearModelFit doesn't work as a function

1 answers, 25 views fitting nonlinear
I use a NonlinearFitModel operation for fitting the piecewised data, and then want to use the result of operation as a function. However, it doesn't work. Could anyone please tell me where can be a ...

### 1 Creating a new list made up by just a particular coordinate of each point in a given set [closed]

0 answers, 24 views list-manipulation fitting
what I'm trying to do is a weighted fit from points on a list that is formatted like: ...

### 2 Is there any reason to use FindFit over NonlinearModelFit? [duplicate]

0 answers, 33 views fitting nonlinear function-comparison
Given that FindFit seems to just be able to return estimated coefficients and none of the other goodies (standard errors, confidence bands, residuals, etc.), under ...

### 1 Optimization of Curve fitting

1 answers, 59 views fitting
I have a set of data: ...

### 2 Curve fitting, Polynomial [closed]

2 answers, 90 views fitting interpolation
I have a data set in such a manner ...

### 2 Fitting a Multi-Exponential Decay With Constraints

1 answers, 68 views fitting constraint
I am having trouble finding a way to fit my data in Mathematica to a multi-exponential decay, with the critical condition that all contributions to the decay sum to 1. To start, I can fit my data to ...

### 13 2D smoothing spline interpolation

3 answers, 1.037 views fitting interpolation splines
Does Mathematica have 2D smoothing spline interpolation built in? I requires an interpolation method with smooth first derivatives and cubic bivariate splines fulfill this nicely. In python I would ...

### 1 Is there a way to find a fit for a specific curve on a Contour Plot?

1 answers, 95 views plotting fitting
I'm kinda new to Mathematica, and it's really giving me a hard time, especially since I'm on a timetable. I have made a contour and I would like to find a function \$u(r)\$ for the part that starts ...

### 2 Fitting multidimensional data

2 answers, 42 views fitting fits-format
Suppose i have some function G[n_,B_,d_] = ....to fit this function i need to collect the data first. However at first i dont understand how to format the data ...

### 1 Finding best fit curve line for a list of data .

2 answers, 67 views plotting fitting
Hi I have a question to find the best average fit curve for a range of data. I have calculated the best fit curve for each sample and plotted them on the same graph. However, I would need to find ...

### How can I find the best fit to my data?

2 answers, 62 views fitting
I have a table of data given by ...

### Plotting line fit

1 answers, 51 views plotting fitting data
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### 4 Multi-peak fitting for peak position

3 answers, 185 views fitting data peak-detection
I have a {x,f} data-set featuring multiple peaks. The peaks evolve with a second variable y. I would like to fit the multiple ...

### 2 How does DimensionReduce work for EventData?

My question is whether the use of DimensionReduce, for a simple example with Method -> "PrincipalComponentsAnalysis" is the ...

### 1 Fitting a function integrated over bins

2 answers, 55 views list-manipulation fitting
My data gives some function integrated over bins of the argument. I want to fit the function with this data. I determine another function with the bin number as the argument and use ...

### 1 NoLinearModelFit error message

1 answers, 60 views fitting
to fit my data, I use the following code. Using Manipulate on my fitting function, I can guess roughly the value for my initial fitting parameter which are in the ...

### 2 Get slope of linear fit

3 answers, 1.004 views fitting
This may seem silly, but I've been crazy for the last hour trying to find a way to automate the linear fit of my data. All I need is the slope. Say I have some data ...

### Fit sine function to my data to find the starting and finishing points [closed]

3 answers, 111 views fitting
Say that I have the following data ...

### Find the corresponding location

0 answers, 45 views list-manipulation fitting estimation
Let's say I have data points (y vs x) << data = https://pastebin.com/FR3xMwk8 >>, and it is shown in here. It is the intensity vs time of two different datasets. I collect some data sample from ...

### 1 FindMinimum wrongly giving a message that the function value is not a real number [closed]

1 answers, 90 views mathematical-optimization fitting
I am trying to use the method of moments to fit parameters to a distribution. This involves minimizing a function. This certainly gives real numbers, but FindMinimum gives an error message saying that ...