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

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5
votes
1answer
206 views

Modeling of soccer results using GeneralizedLinearModelFit

I am trying to recreate the regression in "Analysis of sports data by using bivariate Poisson models," which can be found here, ...
-3
votes
0answers
35 views

Polynomial Equation/Function With Even Degree Order [on hold]

I have the following data for $x$ and $y$ axis, which I am reading from an Excel file by using the Import command and plotting by using the ...
-2
votes
0answers
31 views

How can I fit two datasets with common fit parameters? [on hold]

I have two datasets, say data1 and data2, which can be modeled by the functions f1[params__] ...
12
votes
2answers
237 views

Fitting Stradivari's scroll

How can I find the simplest curve that gives me a scroll like this? This is where I am at the moment and doing it by hand is becoming more and more cumbersome. First, take a drawing of the scroll ...
3
votes
1answer
67 views

Finding NonlinearModelFit of multiple data sets with the same parameters and in two dimensions

I have multiple sets of data (between 3 and 6 depending on the cases) dependent of space, time, and some parameters. The data are the response of a harmonic oscillator under a non-trigonometrical ...
0
votes
0answers
38 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 ...
1
vote
0answers
39 views

NonlinearModelFit with constraints error estimate integrity

I use NonlinearModelFit with additional constraints on the fitting parameteres. When I use "ParameterErrors" or ...
34
votes
3answers
763 views

What is behind experimental function: FindFormula?

In version 10.2 there is a new experimental function: FindFormula[]. I suspect that a genetic programming algorithm (symbolic regression) is behind this new ...
0
votes
2answers
100 views

A case of complicated fitting of multiple datasets

I've stumbled upon a difficulty while trying to do some fitting which may be called sorta complicated. I'll try to introduce my problem step by step. To begin with, I have a number of datasets ...
3
votes
3answers
92 views

Fitting problem

I have two points stored in data: data = {{0.0166667, 2.86927*10^-12}, {0.0333333, 1.12725*10^-11}}; ...
0
votes
0answers
39 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 ...
1
vote
2answers
80 views

List argument for NonlinearModelFit

If I have a function of list argument (presumably with large number of entries), how can I pass it to NonlinearModelFit? I don't want to pass it by pattern checking ...
0
votes
2answers
69 views

Find min-max for slope in linear fit

I have a following data which follows a linear model with intercept zero, i.e. $$y = mx $$ ...
1
vote
1answer
81 views

Sum to Zero Constraint in GeneralizedLinearModelFit

Is there a way to impose a constraint on a generalized linear model fit in Mathematica? In R, when using the glm() function, you can set options(contrasts=c('YY.sum', 'ZZ.sum')). Is there something ...
0
votes
0answers
55 views

Exact meaning of `VarianceEstimatorFunction`

After reading the documentation, it's still unclear for me what VarianceEstimatorFunction does when fed with two arguments: ...
0
votes
0answers
42 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 ...
1
vote
0answers
35 views

Fitting Data when both Variables Have Uncertainties [duplicate]

Does there exist a method in Mathematica for fitting some function f(x; a, b)=y (with parameters a, b) to data of the form {x, y} when both x and y have different uncertainties? It seems like it would ...
0
votes
1answer
86 views

How to Find minimum and maximum using `FindMaximum[]` and `FindMinimum[]`

this is the data that i use to plot. data_damped_osccilation this is my code so far, however it still give me error ...
0
votes
2answers
58 views
3
votes
2answers
216 views

Is there is a decreasing function that fits my data?

Cross-posted in http://tieba.baidu.com/p/4440556337 http://tieba.baidu.com/p/4440547130 I was wondering if there is a function that fits the following data perfectly or properly. There is a ...
1
vote
1answer
84 views

Standard error of linear fit parameters

I fitted data belonging to a MSD (mean squared displacement of a vibrating micrometer sized particle) by using a linear function: ...
0
votes
1answer
44 views

Failed to extract parameters by fitting data with ODE

I'm trying to extract 4 parameters by fitting one set of data with an ODE via NonlinearModelFit. I originally thought the process should be straightforward, but later on I found I was totally wrong. ...
3
votes
2answers
245 views

Why can't FindFit get the proper result in this problem?

Cross-posted in http://tieba.baidu.com/p/4425634583 The mathematica helps me solve one differential equation in numerial method and got the data of the answer,but the taylor series fit is not good in ...
10
votes
4answers
1k views

How can I compute and plot the 95% confidence bands for a fitted logistic regression model?

I have a set of binary data that I' d like to fit a logistic regression model to and show the 95% confidence band around the fitted function. I can produce the regression model but how do I compute ...
0
votes
1answer
35 views

NonlinearModelFit for analytical data is giving errors [closed]

"x is lambda, y is alpha, z is the factor of pressure" ...
0
votes
0answers
38 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 ...
0
votes
0answers
69 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 ...
0
votes
1answer
57 views

FindFit only fitting portions of data

I'm currently trying to fit some complicated data sets and I am having some luck. The higher temperature data works just fine with FindFit. Unfortunately, ...
0
votes
0answers
44 views

Plotting error bars in both dimensions for straight line model [duplicate]

I want to fit a straight line model of the form $y_i = a+ b\ x_i$ to the list of $(x, y)$ pairs given below. How can I plot the data with error bars in both coordinates? ...
2
votes
1answer
81 views

Fitting EV charging curve

I would like to fit my set of data (x = time and y = power) as seen below, and obtain function of x describing it as close as possible, in order to manipulate it (applying different SOC, time offsets ...
13
votes
5answers
1k views

Fit image of mountain to gaussian

I want to detect the edges of an image of a mountain and then fit that to a gaussian. I am unsure about how to only get the mountain edge, rather than every single edge in the image. How do I ...
0
votes
2answers
53 views

Plotting plane from a matrix or data table

After weeks collecting data I've decided to pass my results through Wolfram Alpha and see what it gets. The results are amazingly useful, specially the plane generated by linear regression. It is ...
1
vote
2answers
70 views

Putting suitable constraints on the `Find` family of functions

Can any of the Find group of functions be used to get a good curve-fit for a range of data, if the value of $f(1)$ is known, and the value of $\lim_{n\rightarrow ...
2
votes
0answers
61 views

Algorithm used by Fit[]

Does anyone know what algorithm Mathematica's basic Fit[] function uses? Is it proprietary? I'm trying to do some pretty basic, linear, polynomial data fitting ...
4
votes
4answers
181 views

Fitting Coxian distribution to some data

I'm trying to fit a transformed (actually shifted to the right) Coxian distribution to some data ( if needed an example set is here Sim data ). I've tried a number of ways for this: ...
-2
votes
1answer
91 views

Computing least squares error [closed]

I have a mathematica subroutine setup that computes the least squares approximation as follows ...
3
votes
1answer
171 views

How to make a diagnostic plot for the regression?

Context I am interested in LinearModelFit, and would like to make diagnostic plots using Mathematica. I cannot find them in Mathematica document center. For example, the following R program makes ...
0
votes
2answers
121 views

No real number fitting double exponential in Mathematica

I am trying to fit a double exponential curve to my data, but I got the error saying there are non real number. Also I tried with starting values for my 4 parameters, but this does not work either. ...
5
votes
0answers
82 views

Ridge and lasso regression missing? [closed]

There is no implemented command to perform ridge or lasso regression? I couldn't find it in the documentation. Might be there are add-on packages I am not aware of.
27
votes
6answers
11k views

Estimate error on slope of linear regression given data with associated uncertainty

Given a set of data, is it possible to create a linear regression which has a slope error that takes into account the uncertainty of the data? This is for a high school class, and so the normal ...
3
votes
0answers
94 views

Writing a function to set up and solve the least squares problem

I have setup the explicit line equation for a given set of points using least-squares approximation and the knots computed below. I have tried extending the same code for use with an arbitrary degree, ...
1
vote
1answer
72 views

Paramter Scans and $\chi^2$ Test in Mathematica

Is there any in-built function or a recommended package that enables one to find, say, 10 Parameters, which are used as boundary conditions in NDSolve, that minimize $\chi^2$? ...
4
votes
1answer
84 views

Fitting real and imaginary parts of a function

I have an analytic form of a function G[w_] = -I*z0*w/(1 + I*z0*w*a) I know this function can be obtained (up to some overall normalization) from solving a ...
5
votes
1answer
180 views

How to fit data to a convolution equation

How to fit data to a convolution equation: ...
6
votes
1answer
95 views

Simulated Annealing, SearchPoints and InitialPoints options set at the same time

I have a function that needs to be minimized. Since the function depends on real-time data (which is fetched every few hours, and the function is redefined according to the new data), I have to run ...
1
vote
0answers
148 views

Fitting data to an Normal Inverse Gaussian distribution

I am using data which I suspect is distributed according to the Normal Inverse Gaussian distribution (NIG). The literature says that the 4 parameters of the NIG distribution can be estimated from the ...
1
vote
2answers
127 views

Problem fitting a exponential function to data points [closed]

finale edit: i found someone who solved my problem via matlab. therefore i wont try out the proposed solutions now, but wont delete my question in case someone might have use for the proposed ...
3
votes
2answers
156 views
0
votes
1answer
686 views

FindMinimum produces error message

I'm trying to solve a logistic regression problem using Mathematica -- more to improve my Mathematica skills than to solve the problem as I have already solved it using Octave. The problem I am ...
1
vote
0answers
47 views

NonLinearModelFit to a Function [closed]

I have a multiple dimension function that is fairly complicated. Instead of simply using Series to get a taylor series of the function, I would rather specify my ...