share/fftpack5/fortran/mradb2.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 MRADB2 (M,IDO,L1,CC,IM1,IN1,CH,IM2,IN2,WA1)
  12       REAL       CC(IN1,IDO,2,L1), CH(IN2,IDO,L1,2), WA1(IDO)
  13 C
  14       M1D = (M-1)*IM1+1
  15       M2S = 1-IM2
  16       DO 101 K=1,L1
  17           M2 = M2S
  18           DO 1001 M1=1,M1D,IM1
  19           M2 = M2+IM2
  20          CH(M2,1,K,1) = CC(M1,1,1,K)+CC(M1,IDO,2,K)
  21          CH(M2,1,K,2) = CC(M1,1,1,K)-CC(M1,IDO,2,K)
  22  1001     CONTINUE
  23   101 CONTINUE
  24       IF (IDO-2) 107,105,102
  25   102 IDP2 = IDO+2
  26       DO 104 K=1,L1
  27          DO 103 I=3,IDO,2
  28             IC = IDP2-I
  29                M2 = M2S
  30                DO 1002 M1=1,M1D,IM1
  31                M2 = M2+IM2
  32         CH(M2,I-1,K,1) = CC(M1,I-1,1,K)+CC(M1,IC-1,2,K)
  33         CH(M2,I,K,1) = CC(M1,I,1,K)-CC(M1,IC,2,K)
  34         CH(M2,I-1,K,2) = WA1(I-2)*(CC(M1,I-1,1,K)-CC(M1,IC-1,2,K))
  35      1  -WA1(I-1)*(CC(M1,I,1,K)+CC(M1,IC,2,K))
  36         CH(M2,I,K,2) = WA1(I-2)*(CC(M1,I,1,K)+CC(M1,IC,2,K))+WA1(I-1)
  37      1  *(CC(M1,I-1,1,K)-CC(M1,IC-1,2,K))
  38  1002          CONTINUE
  39   103    CONTINUE
  40   104 CONTINUE
  41       IF (MOD(IDO,2) .EQ. 1) RETURN
  42   105 DO 106 K=1,L1
  43           M2 = M2S
  44           DO 1003 M1=1,M1D,IM1
  45           M2 = M2+IM2
  46          CH(M2,IDO,K,1) = CC(M1,IDO,1,K)+CC(M1,IDO,1,K)
  47          CH(M2,IDO,K,2) = -(CC(M1,1,2,K)+CC(M1,1,2,K))
  48  1003     CONTINUE
  49   106 CONTINUE
  50   107 RETURN
  51       END