C^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^                
      SUBROUTINE GSTSCA(IPRE,EPP) 
C^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^                
      IMPLICIT REAL(A-H,O-Y)                                          
      IMPLICIT COMPLEX(Z)                                            
      INCLUDE 'PACVPP' 
      REAL EPP(3,3),ERE(3,3),EPCI(3,3)
C     SXX, SXY, SXZ
C     SYX, SYY, SYZ
C     SZX, SZY, SZZ
C     X         Y         Z
C 1   ALTV(1,1),ALTV(2,1),ALTV(3,1)   AX1,AY1,AZ1
C 2   ALTV(1,2),ALTV(2,2),ALTV(3,2)   AX2,AY2,AZ2
C 3   ALTV(1,3),ALTV(2,3),ALTV(3,3)   AX3,AY3,AZ3
C 
C     CALCULATE INVERSE MATRIX OF STRESS
      SXX=EPP(1,1)
      SXY=EPP(1,2)
      SXZ=EPP(1,3)
      SYY=EPP(2,2)
      SYZ=EPP(2,3)
      SZZ=EPP(3,3)
C
      ADJA=SXX*SYY*SZZ+2.0D0*SXY*SXZ*SYZ-SXZ*SXZ*SYY-SYZ*SYZ*SXX
     &    -SXY*SXY*SZZ
      ADJAI=1.0D0/ADJA
C
      ERE(1,1)=ADJAI*(SYY*SZZ-SYZ*SYZ)
      ERE(1,2)=ADJAI*(SYZ*SXZ-SZZ*SXY)
      ERE(1,3)=ADJAI*(SXY*SYZ-SXZ*SYY)
      ERE(2,1)=ERE(1,2)
      ERE(2,2)=ADJAI*(SZZ*SXX-SXZ*SXZ)
      ERE(2,3)=ADJAI*(SXZ*SXY-SXX*SYZ)
      ERE(3,1)=ERE(1,3)
      ERE(3,2)=ERE(2,3)
      ERE(3,3)=ADJAI*(SXX*SYY-SXY*SXY)
C     CHECK!
      DO 2000 I=1,3
      DO 2100 J=1,3
      EPCI(I,J)=EPP(I,1)*ERE(1,J)+EPP(I,2)*ERE(2,J)
     &         +EPP(I,3)*ERE(3,J)
 2100 CONTINUE
 2000 CONTINUE
C
      WRITE (6,*) 'CHECK! EPP*ERE'
      WRITE (6,*) EPCI(1,1),EPCI(1,2),EPCI(1,3)
      WRITE (6,*) EPCI(2,1),EPCI(2,2),EPCI(2,3)
      WRITE (6,*) EPCI(3,1),EPCI(3,2),EPCI(3,3)
C
      DO 1000 I=1,KNG
      GXX  =ERE(1,1)*GX(I)+ERE(1,2)*GY(I)+ERE(1,3)*GZ(I)
      GYY  =ERE(2,1)*GX(I)+ERE(2,2)*GY(I)+ERE(2,3)*GZ(I)
      GZZ  =ERE(3,1)*GX(I)+ERE(3,2)*GY(I)+ERE(3,3)*GZ(I)
      GX(I)=GXX
      GY(I)=GYY
      GZ(I)=GZZ 
      GR(I)=SQRT(GX(I)*GX(I)+GY(I)*GY(I)+GZ(I)*GZ(I))
 1000 CONTINUE
C
C     ERE(1,1)=1.0D0/EPP(1,1)                                           
C     ERE(2,2)=1.0D0/EPP(2,2)                                           
C     ERE(3,3)=1.0D0/EPP(3,3) 
      RETURN                                                            
      END