This module provides Piessens Algorithm 473 from the Communications of the ACM, January 1974, Volume 17, Number 1.
Its unrestricted use in a computer is permitted.
This Algorithm transforms a known Chebyshev expansion into a Legendre expansion in N^2 time complexity.
Subroutine to convert Chebyshev (A) to Legendre (B) coefficients.
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
real(kind=rk), | intent(in) | :: | A(n) |
Known coefficients of the Chebyshev approximation. |
||
real(kind=rk), | intent(out) | :: | B(n) |
Computed corresponding coefficients of the Legendre approximation. |
||
integer, | intent(in) | :: | n |
Number of coefficients. |