Scilab comes preloaded with a variety of functions to handle the Bessel and Modified Bessel Functions of First and Second Kind.
These are:
besseli
Modified Bessel functions of the first kind (I sub alpha).
besselj
Bessel functions of the first kind (J sub alpha).
besselk
Modified Bessel functions of the second kind (K sub alpha).
bessely
Bessel functions of the second kind (Y sub alpha).
besselh
Bessel functions of the third kind (aka Hankel functions)
Calling Sequence
y = besselj(alpha,x [,ice])
y = besselk(alpha,x [,ice])
y = bessely(alpha,x [,ice])
y = besselh(alpha,x)
y = besselh(alpha,K,x [,ice])
Arguments
 x

real or complex vector.
 alpha

real vector
 ice

integer flag, with default value 0
 K

integer, with possible values 1 or 2, the Hankel function type.
Now our objective is to plot the First 6 Bessel Functions of the First Kind.
So I am going to use besselj(alpha,x) .
The following code which is pretty much selfexplanatory calculates and plots the First six Bessel Functions, that is J0(x), J1(x), J2(x),…,J5(x).
//Bessel Functions of the First Kind //Plotting some Bessel Functions clf; x=[0:0.01:20]'; alpha=0:5; y=besselj(alpha,x); plot2d(x,y,leg='[email protected]@[email protected]@[email protected]'); xlabel('x'); ylabel('Ja(x)'); xtitle('Some Bessel Functions of the first kind');
Video Tutorials: