share/fftpack5/fortran/sinqmf.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 SINQMF (LOT, JUMP, N, INC, X, LENX, WSAVE, LENSAV,
  12      1                   WORK, LENWRK, IER)
  13       INTEGER    LOT, JUMP, N, INC, LENX, LENSAV, LENWRK, IER
  14       REAL       X(INC,*), WSAVE(LENSAV), WORK(LENWRK)
  15       LOGICAL    XERCON
  16 C
  17       IER = 0
  18 C
  19       IF (LENX .LT. (LOT-1)*JUMP + INC*(N-1) + 1) THEN
  20         IER = 1
  21         CALL XERFFT ('SINQMF', 6)
  22         GO TO 300
  23       ELSEIF (LENSAV .LT. 2*N + INT(LOG(REAL(N))/LOG(2.)) +4) THEN
  24         IER = 2
  25         CALL XERFFT ('SINQMF', 8)
  26         GO TO 300
  27       ELSEIF (LENWRK .LT. LOT*N) THEN
  28         IER = 3
  29         CALL XERFFT ('SINQMF', 10)
  30         GO TO 300
  31       ELSEIF (.NOT. XERCON(INC,JUMP,N,LOT)) THEN
  32         IER = 4
  33         CALL XERFFT ('SINQMF', -1)
  34         GO TO 300
  35       ENDIF
  36 C
  37       IF (N .EQ. 1) RETURN
  38       NS2 = N/2
  39       LJ = (LOT-1)*JUMP+1
  40       DO 101 K=1,NS2
  41          KC = N-K
  42          DO 201 M=1,LJ,JUMP
  43          XHOLD = X(M,K)
  44          X(M,K) = X(M,KC+1)
  45          X(M,KC+1) = XHOLD
  46  201     CONTINUE
  47   101 CONTINUE
  48       CALL COSQMF (LOT,JUMP,N,INC,X,LENX,WSAVE,LENSAV,WORK,LENWRK,IER1)
  49       IF (IER1 .NE. 0) THEN
  50         IER = 20
  51         CALL XERFFT ('SINQMF',-5)
  52         GO TO 300
  53       ENDIF
  54       DO 102 K=2,N,2
  55          DO 202 M=1,LJ,JUMP
  56          X(M,K) = -X(M,K)
  57  202     CONTINUE
  58   102 CONTINUE
  59   300 CONTINUE
  60       RETURN
  61       END