!CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
!                                                                       
!   FFTPACK 5.0                                                         
!                                                                       
!   Authors:  Paul N. Swarztrauber and Richard A. Valent                
!                                                                       
!   $Id: c1fm1b.f,v 1.2 2004/06/15 21:08:32 rodney Exp $                
!                                                                       
!CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
                                                                        
      SUBROUTINE C1FM1B (N,INC,C,CH,WA,FNF,FAC) 
      COMPLEX       C(*) 
      REAL       CH(*),     WA(*),     FAC(*) 
!                                                                       
! FFTPACK 5.0 auxiliary routine                                         
!                                                                       
      INC2 = INC+INC 
      NF = FNF 
      NA = 0 
      L1 = 1 
      IW = 1 
      DO 125 K1=1,NF 
         IP = FAC(K1) 
         L2 = IP*L1 
         IDO = N/L2 
         LID = L1*IDO 
         NBR = 1+NA+2*MIN(IP-2,4) 
         GO TO (52,62,53,63,54,64,55,65,56,66),NBR 
   52    CALL C1F2KB (IDO,L1,NA,C,INC2,CH,2,WA(IW)) 
         GO TO 120 
   62    CALL C1F2KB (IDO,L1,NA,CH,2,C,INC2,WA(IW)) 
         GO TO 120 
   53    CALL C1F3KB (IDO,L1,NA,C,INC2,CH,2,WA(IW)) 
         GO TO 120 
   63    CALL C1F3KB (IDO,L1,NA,CH,2,C,INC2,WA(IW)) 
         GO TO 120 
   54    CALL C1F4KB (IDO,L1,NA,C,INC2,CH,2,WA(IW)) 
         GO TO 120 
   64    CALL C1F4KB (IDO,L1,NA,CH,2,C,INC2,WA(IW)) 
         GO TO 120 
   55    CALL C1F5KB (IDO,L1,NA,C,INC2,CH,2,WA(IW)) 
         GO TO 120 
   65    CALL C1F5KB (IDO,L1,NA,CH,2,C,INC2,WA(IW)) 
         GO TO 120 
   56    CALL C1FGKB (IDO,IP,L1,LID,NA,C,C,INC2,CH,CH,2,                &
     &     WA(IW))                                                      
         GO TO 120 
   66    CALL C1FGKB (IDO,IP,L1,LID,NA,CH,CH,2,C,C,                     &
     &     INC2,WA(IW))                                                 
  120    L1 = L2 
         IW = IW+(IP-1)*(IDO+IDO) 
         IF(IP .LE. 5) NA = 1-NA 
  125 END DO 
      RETURN 
      END