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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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Roots of implicit function including integral of modified Bessel function - symbolic variables not compatible with fzero

I'm trying to solve equation f for r, as below: syms rho C0 = 0.5; a_bar = sqrt(-log((1-C0)/(1+C0))); l = 0.77; f = @(r) exp(-r^2)*int(rho*exp(-rho^2)*besseli(0,2*r*rho),rho,0,a_bar)-(l-1)*int(rho*exp(-rho^2),rho,0,a_bar); r1 = fzero(f,1); However…
alg
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Using bessel functions in MATLAB

I'm trying to put all of my functions from Excel workbook into MATLAB. I'm having an issue using bessel functions in MATLAB. I'm simply not getting the same results from MATLAB as I do in excel. For example, in excel if I…
user2924294
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BesselK Function in C#

I am attempting to implement the BesselK method from Boost (a C++ library). The Boost method accepts two doubles and returns a double. (I have it implemented below as cyl_bessel_k .) The equation I modeled this off of comes from Boosts…
neonScarecrow
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Maple 18: Integral of modified bessel function

I try to calculate the following integral by Maple 18: int(BesselK(1, x)/x^3, x); The result is: (1/16)*MeijerG([[1], []], [[-1/2, -3/2], [0]], (1/4)*x^2) However, when I calculate the derivation of the above result, I didn't get the same…
user2863620
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Plotting the airy disk pattern in MATLAB

So the formula for the airy pattern is with J being the Bessel function besselj(1,x) in MatLab. How would i plot this and approximate it for just the x values of 0-10?
bobby
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Quenching for a long cylinder in matlab using besels function

Supposedly a cylinder is heated to very high temperature and is quenched into a quenchant where the surrounding temperature is at non zero temperature i.e., T0 and initial temperature of cylinder is Ti. The equation is to find out the temperature…
Neethi Sushanthi
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Is there a more pythonic way to write

Learning to be pythonic in 2.7. Is there a way to avoid the explicit loop? answer = [5, 4, 4, 3, 3, 2] import numpy as np import scipy.special as spe nmax = 5 # n = 0, 1 ...5 mmax = 7 # m = 1, 2 ...7 big = 15. z = np.zeros((nmax+1,…
uhoh
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Vectorization - Sum and Bessel function

Can anyone help vectorize this Matlab code? The specific problem is the sum and bessel function with vector inputs. Thank you! N = 3; rho_g = linspace(1e-3,1,N); phi_g = linspace(0,2*pi,N); n = 1:3; tau = [1 2.*ones(1,length(n)-1)]; for ii =…
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Matlab custom spherical bessel function NaN at 0

I have a problem involved spherical Bessel functions of order 0. I wrote my own spherical Bessel function: function js = sphbesselj(nu,x) js = sqrt(pi ./(2* x)) .* besselj(nu + 0.5, x); end which seems to agree with Mathematicas inbuilt one for all…
Steve Hatcher
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calculating bessel function of zero order in matlab

J(x)= 1/π integral cos(xsintheta). limits are from 0 to π. Plot J(2pid/λ) as a function of d/λ in MATLAB for d/λ ranging between 0 and 2. At what distance of separation (in wavelengths) is the correlation between the antennas 0.7, 0 ? I do not…
user1398405
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Bessel function on CUDA to within some epsilon

I try to execute Bessel functions( J0(x) as example) using CUDA. Heres the formula I try to get result to within some epsilon value. So here's the code __device__ void Bessel_j0(int totalBlocks, int totalThreads, float z, float epsilon, float*…
DanilGholtsman
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bessel function math in cylindrical waveguide modes in python

In theory shown bellow,we need to find p' which are the roots of the bessel function derivative. its used for cylindrical structure. can i please have an example (maybe in python) on how exactly they got p'03=10.174 in the table bellow?…
lub2354
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Computing logarithmic derivatives of modified Bessel function of the second kind

I want to know how I can compute the first and second derivatives of logarithm of modified Bessel function of the second kind. For instance, I'm interested in finding the following derivatives with respect to x: ∂/∂x log(K_(x)) ∂^2/∂x^2…
S S
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Bessel function squence integration

Newbie in python, wondering what would be the best strategy for the below I have plotted the below function. z-n is an array (the n terms of a sequence in fact). Theta and r are mesh grids others are single values iv is the modified bessel function…
hecube
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Symbolic Determinant in Python, involving Bessel functions

I'm trying to find the symbolic determinant of a 4x4 matrix that has bessel functions (and their derivatives) in every element. I successfully managed this in matlab, but I'm trying to learn Python by moving the project over. For context, I'm trying…
Cameron Sprent
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