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Questions tagged [data-fitting]

Data fitting is to fit a line through a data set i.e. a series of data points.

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How to get error estimates for fit parameters in scipy.stats.gamma.fit?

I have some which I am fitting to the gamma distribution using scipy.stats. I am able to extract the shape, loc, and scale params and they look reasonable with the data ranges I expect. My question is: is there a way to also get the errors in the…
iluvatar
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Fit a distribution to a histogram

I want to know the distribution of my data points, so first I plotted the histogram of my data. My histogram looks like the following: Second, in order to fit them to a distribution, here's the code I wrote: size = 20000 x = scipy.arange(size) #…
aloha
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Fit a 3D line to 3D point data in Java?

I've spent a decent amount of time trying to hunt down a simple way of doing this - ideally, a magical library exists out there somewhere that will take my set of 3D data points and return 2 points on the best fit line using either orthogonal…
zaczap
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Lorentzian scipy.optimize.leastsq fit to data fails

Since I took a lecture on Python I wanted to use it to fit my data. Although I have been trying for a while now, I still have no idea why this is not working. What I would like to do Take one data-file after another from a subfolder (here called:…
user2082635
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Python power law fit with upper limits & asymmetric errors in data using ODR

I'm trying to fit some data to a power law using python. The problem is that some of my points are upper limits, which I don't know how to include in the fitting routine. In the data, I have put the upper limits as errors in y equal to 1, when the…
astrostudent
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Is there a GNU Octave equivalent for the Matlab function "fit"?

My teacher in the signal analysis course has given me some Matlab code that I have to execute in order to complete a home assignment. I have always been using GNU Octave without troubles, but this time there is this command that is giving me…
wizclown
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Fit a shape to points

I am trying to fit known well-defined shapes (eg boxes, cylinders; with configurable positions, rotations and dimensions) to a set of points with normals generated from sampling a 3D mesh. My current method is to define a custom fit function for…
Epic Wink
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Does name and order of Features matter for prediction algorithm

Do the names/order of the columns of my X_test dataframe have to be the same as the X_train I use for fitting? Below is an example I am training my model with: model.fit(X_train,y) where X_train=data['var1','var2'] But then during prediction, when…
Tartaglia
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How can I fit two linear functions to a set of data points?

I have a set of data points, which appear sort of like a line with a curve near the beginning. See the image below, which shows the points with a line of best fit (fit to the whole data set). Instead, they could be described by two linear functions…
curious_cosmo
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Least square method in python?

I have these values: T_values = (222, 284, 308.5, 333, 358, 411, 477, 518, 880, 1080, 1259) (x values) C/(3Nk)_values = (0.1282, 0.2308, 0.2650, 0.3120 , 0.3547, 0.4530, 0.5556, 0.6154, 0.8932, 0.9103, 0.9316) (y values) I know they follow the…
Philipp
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Getting covariance matrix of fitted parameters from scipy optimize.least_squares method

I am using scipy.optimize's least_squares method in order to perform a constrained non-linear least squares optimization. I was wondering how I would go about getting the covariance matrix of the fitted parameters in order to get error bars on the…
user19346
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gnuplot - Does `set xrange [x_min:x_max]` limit the ranged used for function fit?

Simple question - the range drawn on a plot can be changed with the set xrange [x_min:x_max] command. Does this command also limit the range used when fitting a function using the data fitting tools in gnuplot? Is there a way to manually specify the…
FreelanceConsultant
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Fitting complex model using Python and lmfit?

I would like to fit ellipsometric data to complex model using LMFit. Two measured parameters, psi and delta, are variables in a complex function rho. I could try with separating problem to real and imaginary part with shared parameters or piecewise…
Jur Kravla
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find robust fit of a model function in noisy signal

I have a noisy signal and a model function, for example: x=linspace(0,20); w=[2 6 -4 5]; y=w(1)*besselj(0,x)+w(2)*besselj(1,x)+w(3)*besselj(2,x)+w(4)*besselj(3,x); y(randi(length(y),[1 10]))=10*rand(1,10)-5; plot(x,y,'x') I thought to use RANSAC…
bla
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How to print Gaussian curve fitting results?

It took me some time but I have used the code below to create myself a Gaussian fit for my x,y data set. import matplotlib.pyplot as plt import numpy as np from scipy.optimize import curve_fit def Gauss(x, a, x0, sigma, offset): return a *…
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