Questions tagged [function-fitting]
62 questions
6
votes
2 answers
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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5
votes
1 answer
gnuplot - get errors on fit parameters, get fit output values as variables, print variable to screen
Initial Question (Partially Answered)
I am using gnuplot's fitting routines to fit a function to some data, and extract a "characteristic decay time constant". (I call this parameter d in my fitting function.)
I have used the script code set fit…
FreelanceConsultant
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4
votes
1 answer
Curve fitting with python error
I'm trying to fit my data to (cos(x))^n. The vale of n in theory is 2, but my data should give me around 1.7. When I define my fitting function and I try curve_fit, I get an error
def f(x,a,b,c):
return a+b*np.power(np.cos(x),c)
param, extras =…
Gabriel Esp
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3
votes
2 answers
Unable to fit data due to "can't multiply sequence by non-int of type 'numpy.float64'" error
I'm trying to fit and plot a simple data in a .txt file with a linear function (a*x+b) using matplotlib and scipy. I run into an error concerning the test function: "can't multiply sequence by non-int of type 'numpy.float64'"
I have tried changing…
Francesco Pettini
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3
votes
1 answer
gnuplot - How can I count the number of entries in a csv file column?
I have a gnuplot code which includes a function fitting routine.
This routine is slow when a large number of data points must be fitted. The number of data points in my input file is variable depending on the parameters of some simulations I am…
FreelanceConsultant
- 13,167
- 27
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- 225
3
votes
1 answer
Fitting function through intervals
I have finite series of intervals of real numbers, Ri = (Rimin, Rimax) and series of real numbers ti, i=1..N.
My goal is to find a function f:R->R, where for each i is f(ti) in interval Ri.
In following image on X axis are ti values under each red…
Matej
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2
votes
1 answer
Python surface fitting of variables of different dimensionto get unknown parameters?
I have a function that includes x and y as independent variables and I want to fit the parameters to the data and function and plot a surface figure. I saw that if the variables have two different dimensions, I can use np.meshgrid(x,y), but then how…
mj1496
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2
votes
1 answer
Using scipy.optimize.curve_fit to fit a piecewise function
I am attempting to write a program that reads two sets data from a .csv file into arrays, and then fits it to a piecewise function. What's most important to me is that these fits are done simultaneously because they have the same parameters. This…
Aaron Rea
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2
votes
1 answer
why curve_fit does not converge for a beta function fit?
I have a small problem with my Python code when I try to fit a beta function to a few points. The problem is that either the solution does not converge (and the result coefficients are nans), or it does nothing (at the results stay the same as my…
Enrique
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2
votes
1 answer
Fitting an N-dimensional parabola in python
I have a set of N samples (N~10000 to 100000) :
(y_i, P_i)
They sample an unknown function :
y = f(P)
In my case, P is a set of n_p parameters with n_p typically around 10.
My aim is to use the samples to find the polynomial of order 2 which…
S.I.
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1
vote
0 answers
How do I fit the Weibull distribution to my dataset?
I'm looking to fit a vector of Floats to the Weibull distribution using the fit() function from Distributions.jl . The error I get is:
ERROR: DomainError with NaN:
Weibull: the condition α > zero(α) is not satisfied.
I've been able to do it for…
Ethan Leonard
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1
vote
1 answer
Optimizing a funcation using Scipy to estimate fitting parameters
I am trying to optimize a function by finding its minimum value using Scipy.
The code must find the values of the variables g and tau that will give the minimum value of MSE.
However, These values must be arrays not scalars. Below is the code
import…
Mhmoud Khadija
- 19
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1
vote
1 answer
Fit a smoothed/cumulative distribution function to data and predict x from given y
I need to fit a smoothed/cumulative distribution function to my data and afterwards be able to predict the x-value by a given y, this is what my code looks like atm but it doesn´t work as expected, because loess probably isn´t the right method (even…
Max_
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1
vote
0 answers
Gaussian fit for Python with two different function
I used the Gaussian fit with 3 gauss to adjust but datai but I utility data that sometimes my curve contains only two Gaussians in it not find the parameter remnants to use and but great an error is what there is a method that but allows to change…
yassine dhifaoui
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1
vote
1 answer
What is causing "TypeError: only size-1 arrays can be converted to Python scalars least_squares" from implementation of scipy.optimize.least_squares
I am attempting to fit a normal distribution to histogram values from seaborn. I am using the following code:
from scipy.optimize import least_squares
from math import exp
def model_normal_dist(x, u):
return x[0]*exp(-((x[1]-u)/x[2])**2)
def…
DrRaspberry
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