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Questions tagged [bessel-functions]

The bessel functions in mathematics are the canonical solutions of Bessel's differential equation for an arbitrary complex number.

The bessel functions in mathematics are the canonical solutions of Bessel's differential equation for an arbitrary complex number. The bessel functions can be applied in programming in various cases - when calculating pressure amplitudes, waves and vibrations, free particle and floating body dynamics, and many others.

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Kelvin function KelvinBer[n,z] in Python

In Mathematica there is the Kelvin function KelvinBer[n,z]. I would need something equivalent in Python with n=0 and n=1. There is scipy.special.ber(x), but as I understand it and played around, it comes with n=0. Is there an already defined…
UweD
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Does numexpr support special bessel functions?

I need to evaluate BesselK function at about ten million points. I know scipy.special supports this as scipy.special.kv(n, x), but I want a faster evaluation as well as a memory efficient evaluation. Ideally numexpr would be good, and I tried…
konstant
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von Mises distribution with gnuplot

I need to fit some data to the von Mises distribution: but before to do that I would like to plot this function first in gnuplot. I want to reproduce the curves for different k values, you can see them in wikipedia:…
Wara
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matrix of special (besselj) functions

I'm new to julia so I would welcome some advice to improve the following function, using SpecialFunctions function rb(x, nu_max) bj = Array{Complex64}(length(x), nu_max) nu = 0.5 + (0:nu_max) # somehow dot broadcast isn't happy # bj .= […
learnjulia
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Numerical integration of highly oscillating 1-D integrand (containing Bessel functions) in python

I am attempting to numerically evaluate a real-valued integrand composed of several Bessel functions (of the first and second kind). The integrand is oscillating and decaying, and needs to be evaluated between 0 and +∞. So far, my attempts using the…
tomatessechees
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Integration of a bessel function in python: subdivision issue

I am trying to integrate on a surface the following equation: intensity=(2*J1(z)/z)^2 with z=A*sqrt((x-mu1)^2+(y-mu2)^2), A(L) a constant of x and y and J1 the first order bessel function. To do so I use the dblquad function as below: resultinf =…
Vincent
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Matlab Negative parameters of Mejier G function

Is it possible that meijerG function contain a negative value (i.e. is {-1,0,0})? I tried both Mathematica and Matlab to compute this meijerG function but they generate an error that this meijerG is not defined for the given parameters`. Here is my…
Baidal Kocham
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Compiling of complex_Bessel_function library - linking with Fortran code - mex file

I have made a .cpp code that uses the following online library: Complex_Bessel_functions. I want to make a .mex file out of my code. When I am typing: mex GUSTAVsolution.cpp Matlab gives the following errors: Error using…
Ilias
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Spherical Bessel Transformation using SymPy

I want to write a Python (with SymPy lib) code that it can make calculations back and forth between Fourier (FT) and inverse Fourier (iFT) Transformation of a function. Let's say there is a function f(r), FT of it g(q) = FT[f(r)] and iFT of new…
hesap
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Multiplying and Dividing by Two

Why are these two snippets of code giving two different results? double sum = 1.0; double xSqFour = x * x / 4; for (int i = 48; i > 1; i-=2) { sum = 1.0 + (xSqFour / ((i/2) * (i/2))) * sum; } return sum; and double…
yodie
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Bessel's integral implementation

I'm trying to implement this integral representation of Bessel function of the first kind of order n. here is what I tried: t = -pi:0.1:pi; n = 1; x = 0:5:20; A(t) = exp(sqrt(-1)*(n*t-x*sin(t))); B(t) = integral(A(t),-pi,pi); plot(A(t),x) the plot…
iamgr007
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Scipy - Error while using spherical Bessel functions

I'm trying to draw plots in Python with Scipy module. According to http://docs.scipy.org/doc/scipy/reference/special.html I wrote code with scipy.special.spherical_jn(n,x,0): import matplotlib.pyplot as plt import numpy as np import scipy.special as…
Jimmy Found
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Calculate second order bessel functions in java with non-integer order

I am trying to calculate second order bessel functions (Y_v(x)) using Java. Where v, the order of the bessel function, is non integer. Apache, I know, has a function to calculated first order bessel functions (J_v(x)) import…
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How can I numerically solve equations containing Bessel functions in MATLAB?

I have confronted an equation containing Bessel functions of the first type on one side and modified Bessel functions of the second type on the other. I want to know its exact solutions (values of u). The equation is as…
Aida
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high order bessel function computation with large variables

My work involves computation of high order bessel function at large variable value. Within MATLAB, this has been done without problems. However, in order to scale up the problem, I have tuned to writing C++ code with MPI. Of course, the step to…
Franklin Dong
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