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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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Bessel functions in Python that work with large exponents

I've got some code that uses the modified Bessel functions of both 1st and 2nd order (iv and kv). Annoyingly they seem to have limits, those are iv(0,713) and kv(0,697), add one to each and you get infinity and 0 respectively. This is a problem for…
Rapid
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Natural Logarithm of Bessel Function, Overflow

I am trying to calculate the logarithm of a modified Bessel function of second type in MATLAB, i.e. something like that: log(besselk(nu, Z)) where e.g. nu = 750; Z = 1; I have a problem because the value of log(besselk(nu, Z)) goes to infinity,…
James Green
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Vectorized spherical bessel functions in python?

I noticed that scipy.special Bessel functions of order n and argument x jv(n,x) are vectorized in x: In [14]: import scipy.special as sp In [16]: sp.jv(1, range(3)) # n=1, [x=0,1,2] Out[16]: array([ 0., 0.44005059, 0.57672481]) But there's no…
Adam Hughes
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Calculate bessel function in MATLAB using Jm+1=2mj(m) -j(m-1) formula

I tried to implement bessel function using that formula, this is the code: function result=Bessel(num); if num==0 result=bessel(0,1); elseif num==1 result=bessel(1,1); else result=2*(num-1)*Bessel(num-1)-Bessel(num-2); end; But if I…
Ramy Al Zuhouri
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Algorithm to calculate modified Bessel function of the first kind

Could you tell me a fast and accurate method to calcuate BesselK(mu,z), BesselI(mu,z), where mu is real number?
minhbsu
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Go: Bessel functions

I noticed that there are functions for first-order, second-order, and N-order Bessel functions (Y0, Y1, Yn) defined in the standard Go library (Y0). I can't seem to determine the practical application of these mathematical functions that would make…
Dustin Oprea
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Hankel function H_n^(2) in TensorFlow

I need to use Hankel functions of the second kind, that is H_n^(2) with n in {0,1,2}, in Tensorflow. http://mathworld.wolfram.com/HankelFunctionoftheSecondKind.html Tensorflow, however, does not have these functions in its standard library. It only…
Time2Lime
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Why does scipy bessel root finding not return roots at zero?

I am trying to use code which uses Bessel function zeros for other calculations. I noticed the following piece of code produces results that I consider unexpected. import scipy from scipy import special scipy.special.jn_zeros(1,2) I…
WolcottR
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Second derivative of the Hankel function unsing sympy

I want to plot the second derivative of the Hankel function using Simpy. In Mathematica it is as easy as: D[HankelH2[1,z],z] This can be done analytically by using the property, The first derivative of the Hankel function of the second kind and…
Felipe BM
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Scipy hangs on finding zeros of Bessel Functions

I'm using the scipy library to find the zeros of the Bessel functions. It seems to work for lower order Bessel functions > jn_zeros(200,6) array([ 211.02916651, 219.51409634, 226.60754246, 232.9865383 , 238.90771104, 244.50236452]) >…
rprospero
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Plotting Bessel function in MATLAB

In MATLAB how do you plot f(r) = { 2*J1(a*r) / r }^2 where a = 2*pi and J1 is Bessel function of the 1st kind and r = sqrt(x^2 + y^2) This should plot in 3D, i.e. kind of be like a bubble (not sure how to do this)
4alala
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Integration of 0-th order Bessel function using MATLAB

I have simple question. I'm trying to evaluate improper integral of 0th order Bessel function using Matlab R2012a: v = integral(@(x)(besselj(0, x), 0, Inf) which gives me v = 3.7573e+09. However this should be v = 1 in theory. When I'm trying to do…
Nikolai Liubimov
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Plotting characteristics of antenna radiation in matlab

I need to plot this function theta = (-pi:0.01:pi); f = 3*10^9; c = 299792458; da = 2; Here's my code, but I'm not sure it's correct. I dont know where exactly dot mark should be. How to set X-Axis in degress? beta = (2*pi*f)/c; const=…
daredesm
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Vectorizing MATLAB function

I have double summation over m = 1:M and n = 1:N for polar point with coordinates rho, phi, z: I have written vectorized notation of it: N = 10; M = 10; n = 1:N; m = 1:M; rho = 1; phi = 1; z = 1; summ = cos (n*z) * besselj(m'-1, n*rho) *…
N0rbert
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How to plot in matlab using the besselh function with a given range of k (reduced frequency)?

I am using a Matlab function called besselh which gives an exact solution to Theoderon's lift deficiency function for a two-dimensional airfoil executing a simple harmonic motion in incompressible flow with a given range of k. I am trying to plot…
Jesus
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