NAME

SYNOPSIS

  SUBROUTINE RFFT2F( PLACE, FULL, M, N, A, LDA, B, LDB, WORK, LWORK)
  CHARACTER * 1 PLACE, FULL
  INTEGER M, N, LDA, LDB, LWORK
  REAL A(LDA,*), B(LDB,*), WORK(*)
 
  SUBROUTINE RFFT2F_64( PLACE, FULL, M, N, A, LDA, B, LDB, WORK, 
 *      LWORK)
  CHARACTER * 1 PLACE, FULL
  INTEGER*8 M, N, LDA, LDB, LWORK
  REAL A(LDA,*), B(LDB,*), WORK(*)
 

F95 INTERFACE

  SUBROUTINE FFT2F( PLACE, FULL, [M], [N], A, [LDA], B, [LDB], WORK, 
 *       LWORK)
  CHARACTER(LEN=1) :: PLACE, FULL
  INTEGER :: M, N, LDA, LDB, LWORK
  REAL, DIMENSION(:) :: WORK
  REAL, DIMENSION(:,:) :: A, B
 
  SUBROUTINE FFT2F_64( PLACE, FULL, [M], [N], A, [LDA], B, [LDB], 
 *       WORK, LWORK)
  CHARACTER(LEN=1) :: PLACE, FULL
  INTEGER(8) :: M, N, LDA, LDB, LWORK
  REAL, DIMENSION(:) :: WORK
  REAL, DIMENSION(:,:) :: A, B
 

C INTERFACE

void rfft2f(char place, char full, int m, int n, float *a, int lda, float *b, int ldb, float *work, int lwork);

void rfft2f_64(char place, char full, long m, long n, float *a, long lda, float *b, long ldb, float *work, long lwork);

ARGUMENTS

* PLACE (input)

Character. If PLACE = 'I' or 'i' (for in-place) , the input and output data are stored in array A. If PLACE = 'O' or 'o' (for out-of-place), the input data is stored in array B while the output is stored in A.

* FULL (input)

Indicates whether or not to generate the full result matrix. 'F' or 'f' will cause RFFT2F to generate the full result matrix. Otherwise only a partial matrix that takes advantage of symmetry will be generated.

* M (input)

Integer specifying the number of rows to be transformed. It is most efficient when M is a product of small primes. M >= 0; when M = 0, the subroutine returns immediately without changing any data.

* N (input)

Integer specifying the number of columns to be transformed. It is most most efficient when N is a product of small primes. N >= 0; when N = 0, the subroutine returns immediately without changing any data.

* A (input/output)

On entry, a two-dimensional array A(LDA,N) that contains the data to be transformed. Upon exit, A is unchanged if an out-of-place transform is done. If an in-place transform with partial result is requested, A(1:(M/2+1)*2,1:N) will contain the transformed results. If an in-place transform with full result is requested, A(1:2*M,1:N) will contain complete transformed results.

* LDA (input)

Leading dimension of the array containing the data to be transformed. LDA must be even if the transformed sequences are to be stored in A.

If PLACE = ('O' or 'o') LDA >= M

If PLACE = ('I' or 'i') LDA must be even. If

FULL = ('F' or 'f'), LDA >= 2*M

FULL is not ('F' or 'f'), LDA >= (M/2+1)*2

* B (input/output)

Upon exit, a two-dimensional array B(2*LDB,N) that contains the transformed results if an out-of-place transform is done. Otherwise, B is not used.

If an out-of-place transform is done and FULL is not 'F' or 'f', B(1:(M/2+1)*2,1:N) will contain the partial transformed results. If FULL = 'F' or 'f', B(1:2*M,1:N) will contain the complete transformed results.

* LDB (input)

2*LDB is the leading dimension of the array B. If an in-place transform is desired LDB is ignored.

If PLACE is ('O' or 'o') and

FULL is ('F' or 'f'), LDB >= M

FULL is not ('F' or 'f') and M is even, LDB >= M/2+1

Note that even though LDB is used in the argument list, 2*LDB is the actual leading dimension of B.

* WORK (input/output)

One-dimensional real array of length at least LWORK. On input, WORK must have been initialized by RFFT2I.

* LWORK (input)

Integer. LWORK >= (M + 2*N + MAX(M, 2*N) + 30)