PDA_NAG2C

Convert NAG complex Fourier transform array into array usable by FFTPACK routine PDA_CFFTB

Description:

This subroutine returns a modified version of the supplied Fourier coefficients (as produced by NAG subroutine C06FCF). An inverse FFT can be performed on the returned array using FFTPACK routine PDA_CFFTB, and the resulting inverse will have the same normalisation as the original data transformed using PDA_CFFTF. See PDA_C2NAG for more details.

Invocation

CALL PDA_NAG2C( NP, X, Y, R )

Arguments

NP = INTEGER (Given)
The number of points in the transform.
X( NP ) = REAL (Given)
The real coefficients, in NAG format.
Y( NP ) = REAL (Given)
The imaginary coefficients, in NAG format.
R( 2, NP ) = REAL (Returned)
The output coefficients, in FFTPACK format.

Implementation Status:

A double precision version PDA_DNAG2C of the routine exists.

Notes:

A call to PDA_C2NAG followed by a call to PDA_NAG2C will result in the original data being divided by NP.