Evaluate the derivative of the Jacobi polynomial of type at points for order .
Type | Intent | Optional | Attributes | Name | ||
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real(kind=wp), | intent(in), | dimension(:) | :: | x | The points at which to evaluate the derivative of the Jacobi polynomial. |
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real(kind=wp), | intent(in) | :: | alpha | The value of . |
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real(kind=wp), | intent(in) | :: | beta | The value of . |
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integer(kind=ip), | intent(in) | :: | n | The order of the Jacobi polynomials. |
The return value is the derivative of the Jacobi polynomial evaluated at ,
function GradJacobiP ( x, alpha, beta, n )
!! Evaluate the derivative of the Jacobi polynomial of type
!! \((\alpha,\beta)>-1\) at points \(x\) for order \(n\).
real(wp), dimension(:), intent(in) :: x
!! The points \(x\in[-1:1]\) at which to evaluate the derivative of the
!! Jacobi polynomial.
real(wp), intent(in) :: alpha
!! The value of \(\alpha\).
real(wp), intent(in) :: beta
!! The value of \(\beta\).
integer(ip), intent(in) :: n
!! The order of the Jacobi polynomials.
real(wp), dimension(size(x)) :: GradJacobiP
!! The return value is the derivative of the Jacobi polynomial evaluated
!! at \(x_i\), \(\left .\frac{dP_n^{(\alpha,\beta)}}{dx}
!! \right |_{x=x_i}\)
if (n==0) then
GradJacobiP = 0.0_wp
return
end if
GradJacobiP = sqrt(n*(n+alpha+beta+1))* &
JacobiP(x,alpha+1.0_wp,beta+1.0_wp,n-1)
return
end function GradJacobiP