Sources Esope | Cast3M

r1f2kb
C R1F2KB    SOURCE    BP208322  18/10/08    21:15:08     9952           
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C   FFTPACK 5.1 
C
C   Authors:  Paul N. Swarztrauber and Richard A. Valent
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
 
      SUBROUTINE R1F2KB (IDO,L1,CC,IN1,CH,IN2,WA1)
      IMPLICIT INTEGER(I-N)
      IMPLICIT REAL*8(A-H,O-Z)
      REAL*8   CC(IN1,IDO,2,L1), CH(IN2,IDO,L1,2), WA1(IDO)
C
      DO 101 K=1,L1
         CH(1,1,K,1) = CC(1,1,1,K)+CC(1,IDO,2,K)
         CH(1,1,K,2) = CC(1,1,1,K)-CC(1,IDO,2,K)
 101  CONTINUE
      IF (IDO-2) 107,105,102
 102  IDP2 = IDO+2
      DO 104 K=1,L1
         DO 103 I=3,IDO,2
            IC = IDP2-I
 
            CH(1,I-1,K,1) = CC(1,I-1,1,K)+CC(1,IC-1,2,K)
            CH(1,I,K,1) = CC(1,I,1,K)-CC(1,IC,2,K)
 
            CH(1,I-1,K,2) = WA1(I-2)*(CC(1,I-1,1,K)-CC(1,IC-1,2,K))
     1           -WA1(I-1)*(CC(1,I,1,K)+CC(1,IC,2,K))
            CH(1,I,K,2) = WA1(I-2)*(CC(1,I,1,K)+CC(1,IC,2,K))+WA1(I-1)
     1           *(CC(1,I-1,1,K)-CC(1,IC-1,2,K))
 
 103     CONTINUE
 104  CONTINUE
      IF (MOD(IDO,2) .EQ. 1) RETURN
 105  DO 106 K=1,L1
         CH(1,IDO,K,1) = CC(1,IDO,1,K)+CC(1,IDO,1,K)
         CH(1,IDO,K,2) = -(CC(1,1,2,K)+CC(1,1,2,K))
 106  CONTINUE
 107  RETURN
      END