Using Bessel function of first kind

I am trying to use the bessel function in MATLAB as follows :

besselj(0,2.4048)= 1.3268e-5

however when i code it like this i get a different answer:

S= 2.4048;

besselj(0,S) = 0;

I am not sure what causes this difference. Can anyone explain why the answer changes? It happens for all values. and the differnce can be up to x10^6 sometimes

[Dyuman Joshi]

Its working fine here.

val1=besselj(0,2.4048)

val1 = 1.3268e-05

s=2.4048;
val2=besselj(0,s)

val2 = 1.3268e-05

Can you show your code? Also, attach the results you are getting.

[David Goodmanson]

Hi Amir, are you possibly getting the S value from some other place? If

S = 2.404825557695773

then in the usual format it is going to show up as

S = 2.4048

although it does not really have that value. Here

besselj(0,S)
  ans =  0

and besselj(0,2.4048) gives the nonzero value you show.

Answer 1

[Sakshay]

Hi Amir,

As per my understanding, you are facing an error while using the “besselj” function. The function doesn’t seem to have any problem like this. It should work the same for both the cases.

besselj(0, 2.4048)

ans = 1.3268e-05

s = 2.4048;
besselj(0, s)

ans = 1.3268e-05

Make sure that you are providing the correct input values to the function.

You can refer to the following documentation on "besselj" function for more information:

Bessel function of first kind - MATLAB besselj (mathworks.com)