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 | ||
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real(kind=rk), | intent(in) | :: | A(n) | Known coefficients of the Chebyshev approximation. |
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real(kind=rk), | intent(out) | :: | B(n) | Computed corresponding coefficients of the Legendre approximation. |
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integer, | intent(in) | :: | n | Number of coefficients. |