!CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
!                                                                       
!   FFTPACK 5.0                                                         
!   Copyright (C) 1995-2004, Scientific Computing Division,             
!   University Corporation for Atmospheric Research                     
!   Licensed under the GNU General Public License (GPL)                 
!                                                                       
!   Authors:  Paul N. Swarztrauber and Richard A. Valent                
!                                                                       
!   $Id: mradb4.f,v 1.2 2004/06/15 21:29:19 rodney Exp $                
!                                                                       
!CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
                                                                        
      SUBROUTINE MRADB4 (M,IDO,L1,CC,IM1,IN1,CH,IM2,IN2,WA1,WA2,WA3) 
      REAL       CC(IN1,IDO,4,L1)  ,CH(IN2,IDO,L1,4)    ,               &
     &           WA1(IDO)  ,        WA2(IDO)  ,       WA3(IDO)          
!                                                                       
      M1D = (M-1)*IM1+1 
      M2S = 1-IM2 
      SQRT2=SQRT(2.) 
      DO 101 K=1,L1 
          M2 = M2S 
          DO 1001 M1=1,M1D,IM1 
          M2 = M2+IM2 
         CH(M2,1,K,3) = (CC(M1,1,1,K)+CC(M1,IDO,4,K))                   &
     &   -(CC(M1,IDO,2,K)+CC(M1,IDO,2,K))                               
         CH(M2,1,K,1) = (CC(M1,1,1,K)+CC(M1,IDO,4,K))                   &
     &   +(CC(M1,IDO,2,K)+CC(M1,IDO,2,K))                               
         CH(M2,1,K,4) = (CC(M1,1,1,K)-CC(M1,IDO,4,K))                   &
     &   +(CC(M1,1,3,K)+CC(M1,1,3,K))                                   
         CH(M2,1,K,2) = (CC(M1,1,1,K)-CC(M1,IDO,4,K))                   &
     &   -(CC(M1,1,3,K)+CC(M1,1,3,K))                                   
 1001     CONTINUE 
  101 END DO 
      IF (IDO-2) 107,105,102 
  102 IDP2 = IDO+2 
      DO 104 K=1,L1 
         DO 103 I=3,IDO,2 
            IC = IDP2-I 
               M2 = M2S 
               DO 1002 M1=1,M1D,IM1 
               M2 = M2+IM2 
        CH(M2,I-1,K,1) = (CC(M1,I-1,1,K)+CC(M1,IC-1,4,K))               &
     &  +(CC(M1,I-1,3,K)+CC(M1,IC-1,2,K))                               
        CH(M2,I,K,1) = (CC(M1,I,1,K)-CC(M1,IC,4,K))                     &
     &  +(CC(M1,I,3,K)-CC(M1,IC,2,K))                                   
        CH(M2,I-1,K,2)=WA1(I-2)*((CC(M1,I-1,1,K)-CC(M1,IC-1,4,K))       &
     &  -(CC(M1,I,3,K)+CC(M1,IC,2,K)))-WA1(I-1)                         &
     &  *((CC(M1,I,1,K)+CC(M1,IC,4,K))+(CC(M1,I-1,3,K)-CC(M1,IC-1,2,K)))
        CH(M2,I,K,2)=WA1(I-2)*((CC(M1,I,1,K)+CC(M1,IC,4,K))             &
     &  +(CC(M1,I-1,3,K)-CC(M1,IC-1,2,K)))+WA1(I-1)                     &
     &  *((CC(M1,I-1,1,K)-CC(M1,IC-1,4,K))-(CC(M1,I,3,K)+CC(M1,IC,2,K)))
        CH(M2,I-1,K,3)=WA2(I-2)*((CC(M1,I-1,1,K)+CC(M1,IC-1,4,K))       &
     &  -(CC(M1,I-1,3,K)+CC(M1,IC-1,2,K)))-WA2(I-1)                     &
     &  *((CC(M1,I,1,K)-CC(M1,IC,4,K))-(CC(M1,I,3,K)-CC(M1,IC,2,K)))    
        CH(M2,I,K,3)=WA2(I-2)*((CC(M1,I,1,K)-CC(M1,IC,4,K))             &
     &  -(CC(M1,I,3,K)-CC(M1,IC,2,K)))+WA2(I-1)                         &
     &  *((CC(M1,I-1,1,K)+CC(M1,IC-1,4,K))-(CC(M1,I-1,3,K)              &
     &  +CC(M1,IC-1,2,K)))                                              
        CH(M2,I-1,K,4)=WA3(I-2)*((CC(M1,I-1,1,K)-CC(M1,IC-1,4,K))       &
     &  +(CC(M1,I,3,K)+CC(M1,IC,2,K)))-WA3(I-1)                         &
     & *((CC(M1,I,1,K)+CC(M1,IC,4,K))-(CC(M1,I-1,3,K)-CC(M1,IC-1,2,K))) 
        CH(M2,I,K,4)=WA3(I-2)*((CC(M1,I,1,K)+CC(M1,IC,4,K))             &
     &  -(CC(M1,I-1,3,K)-CC(M1,IC-1,2,K)))+WA3(I-1)                     &
     &  *((CC(M1,I-1,1,K)-CC(M1,IC-1,4,K))+(CC(M1,I,3,K)+CC(M1,IC,2,K)))
 1002          CONTINUE 
  103    CONTINUE 
  104 END DO 
      IF (MOD(IDO,2) .EQ. 1) RETURN 
  105 CONTINUE 
      DO 106 K=1,L1 
               M2 = M2S 
               DO 1003 M1=1,M1D,IM1 
               M2 = M2+IM2 
         CH(M2,IDO,K,1) = (CC(M1,IDO,1,K)+CC(M1,IDO,3,K))               &
     &   +(CC(M1,IDO,1,K)+CC(M1,IDO,3,K))                               
         CH(M2,IDO,K,2) = SQRT2*((CC(M1,IDO,1,K)-CC(M1,IDO,3,K))        &
     &   -(CC(M1,1,2,K)+CC(M1,1,4,K)))                                  
         CH(M2,IDO,K,3) = (CC(M1,1,4,K)-CC(M1,1,2,K))                   &
     &   +(CC(M1,1,4,K)-CC(M1,1,2,K))                                   
         CH(M2,IDO,K,4) = -SQRT2*((CC(M1,IDO,1,K)-CC(M1,IDO,3,K))       &
     &   +(CC(M1,1,2,K)+CC(M1,1,4,K)))                                  
 1003          CONTINUE 
  106 END DO 
  107 RETURN 
      END