SUBROUTINE GRPH3D(ZV,SX,DX,SY,DY,MX,NX,MY,NY,IAX)
      DIMENSION ZV(NX,NY)
      COMMON/C3D/ZU(200),AA,BB,CC,HDYN,IN
      LOGICAL READY
      CALL COM3D(ZV,SX,DX,SY,DY,MX,NX,MY,NY,IAX,B,C,F,HDY,XM,YM)
      M=NX-MX
      M1=M-1
      N=200/M
      N1=N*M1
      HDYN=HDY/FLOAT(N)
      Y=ZV(MX,MY)+B
      CALL POINT(C,Y)
      I=MX
      IN=0
      DO 123 I1=1,M1
      I=I+1
      X2=I1*HDY+C
      X1=X2-HDY
      X3=X2+HDY
      CALL QUADFI(X1,ZV(I-1,MY)+B,X2,ZV(I,MY)+B,X3,ZV(I+1,MY)+B,
     1AA,BB,CC)
      DO 123 I2=1,N
 123  CALL CJOIN(C)
      DO 124 I2=1,N
 124  CALL CJOIN(C)
      IMY=MY+1
      DO 150 J=IMY,NY
      D=(J-MY)*HDY
      A=B+D
      D=C+D
      Y=A+ZV(MX,J)
      CALL POINT(D,Y)
      DO 100 IN=1,N1
 100  ZU(IN)=ZU(IN+N)
      READY=Y.GE.ZU(1)
      I=MX
      IN=0
      DO 149 I1=1,M1
      I=I+1
      X2=I1*HDY+D
      X1=X2-HDY
      X3=X2+HDY
      CALL QUADFI(X1,ZV(I-1,J)+A,X2,ZV(I,J)+A,X3,ZV(I+1,J)+A,AA,BB,CC)
      DO 149 I2=1,N
      IN=IN+1
      X=IN*HDYN+D
      Y=AA*X*X+BB*X+CC
      IF(Y.LT.ZU(IN)) GOTO 147
      ZU(IN)=Y
      IF(.NOT.READY) GOTO 145
      CALL JOIN(X,Y)
      GOTO 149
 145  READY=.TRUE.
      CALL POINT(X,Y)
      GOTO 149
 147  READY=.FALSE.
 149  CONTINUE
      IF(.NOT.READY) CALL POINT(X,Y)
      DO 150 I2=1,N
      CALL CJOIN(D)
 150  CONTINUE
      RETURN
      END
      SUBROUTINE CJOIN(C)
      COMMON/C3D/ZU(200),AA,BB,CC,HDYN,IN
      IN=IN+1
      X=IN*HDYN+C
      Y=AA*X*X+BB*X+CC
      ZU(IN)=Y
      CALL JOIN(X,Y)
      RETURN
      END
      SUBROUTINE QUADFI(X1,Y1,X2,Y2,X3,Y3,A,B,C)
      T1=X3-X2
      T2=X1-X3
      T3=X2-X1
      T4=-T1*(X2+X3)
      T5=-T2*(X3+X1)
      T6=-T3*(X1+X2)
      D=1.0/(X1*T4+X2*T5+X3*T6)
      A=D*(Y1*T1+Y2*T2+Y3*T3)
      B=D*(Y1*T4+Y2*T5+Y3*T6)
      C=D*(Y1*X2*X3*T1+Y2*X1*X3*T2+Y3*X1*X2*T3)
      RETURN
      END