share/fftpack5/fortran/rfft1b.f

   1 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
   2 C
   3 C   FFTPACK 5.0
   4 C
   5 C   Authors:  Paul N. Swarztrauber and Richard A. Valent
   6 C
   7 C   $Id$
   8 C
   9 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
  10
  11       SUBROUTINE RFFT1B ( N, INC, R, LENR, WSAVE, LENSAV,
  12      1                  WORK, LENWRK, IER)
  13       INTEGER  N, INC, LENR, LENSAV, LENWRK, IER
  14       REAL     R(LENR), WSAVE(LENSAV)     ,WORK(LENWRK)
  15 C
  16       IER = 0
  17 C
  18       IF (LENR .LT. INC*(N-1) + 1) THEN
  19         IER = 1
  20         CALL XERFFT ('RFFT1B ', 6)
  21       ELSEIF (LENSAV .LT. N + INT(LOG(REAL(N))/LOG(2.)) +4) THEN
  22         IER = 2
  23         CALL XERFFT ('RFFT1B ', 8)
  24       ELSEIF (LENWRK .LT. N) THEN
  25         IER = 3
  26         CALL XERFFT ('RFFT1B ', 10)
  27       ENDIF
  28 C
  29       IF (N .EQ. 1) RETURN
  30 C
  31       CALL RFFTB1 (N,INC,R,WORK,WSAVE,WSAVE(N+1))
  32       RETURN
  33       END