Jacobi polynomials in MATLAB

i want to execute jacobi polynomials for N = j-3 where j= 0, 1,...,4, a = b = 3 and x = -0.655, the code according to my knowledge will be,

syms j

a= 3;

b=3;

for j = 0:4

    display (jacobiP(j-3,3,3,-0.655))

 end

but this code isn't working kindly guide me.

Answer 1

[Karan Gill]

Your first argument "j-3" is negative for j=0,1,2. That's what the error message says: A nonnegative integer or a symbol is expected.

If you replace "j-3" with "j" it works.

syms j
a= 3;
b=3;
for j = 0:4
jacobiP(j,3,3,-0.655)
end

ans =
     1
ans =
   -2.6200
ans =
    3.5765
ans =
   -2.8153
ans =
    0.4398

[R shah]

thx sir, but i know this information i also know that jacobi polynomials are defined for n >= 0 but when we take the third derivative of jacobi polynomial we got the jacobi P(j-3, a+3, b+3, -0.655) i've taken the case when a = 0 and b = 0 so i must have to evaluate jacobiP(j-3, 3,3,-0.655). should i consider the values:

0 for j = 0

0 for j = 1

0 for j = 2

-2.,815 for j = 3

0.4398 for j = 4

[R shah]

whats wrong if i take this code for above problem

    clc; clear all 
  syms j
  a = 3 ;
  b = 3 ;

for j = 0:4
  if  j-3 == -3:-1
     display(jacobiP(j-3,3,3,0.655) == 0)
  else  
   display(jacobiP(j-3,3,3,0.655))
  end
end