C DERI2     SOURCE    CB215821  26/08/24    21:16:04     12622          
      SUBROUTINE DERI2(D2FSIG,DPHI,P,S,NSTRS,BETJEF)
C
      IMPLICIT INTEGER(I-N)
      IMPLICIT REAL*8 (A-H,O-Z)
      DIMENSION S(4),P(4,4),D2FSIG(4,4)
      DIMENSION AB(4),AC(4),DP(4,4),P1(4,4)
*
      SEGMENT BETJEF
       REAL*8 AA,BETA,RB,ALPHA,EX,PXY,GFC,GFT,CAR,ETA,TDEF,
     &          TCON,DPSTF1,DPSTF2,TETA,PDT
       INTEGER ICT,ICC,IMOD,IVISS,ITER,
     &                ISIM,IBB1,IGAU1,IZON
      ENDSEGMENT
*
*     COMMON /DBETJEF/AA,BETA,RB,ALPHA,EX,PXY,GFC,GFT,CAR,ETA,TDEF,
*    &          TCON,DPSTF1,DPSTF2,TETA,PDT,ICT,ICC,IMOD,IVISS,ITER,
*    &                ISIM,IBB1,IGAU1,IZON
C             *************************************************
C             **  CALCUL DE LA DERIVE SECONDE DU CRITERE     **
C             *************************************************
C-------------------------------------------------------------------
      DO 10 I=1,NSTRS
        AB(I)=0.D0
      DO 1 J=1,NSTRS
        AB(I)=AB(I)+P(I,J)*S(J)
    1 CONTINUE
   10 CONTINUE
C
      DO 11 I=1,NSTRS
        AC(I)=0.D0
      DO 6 J=1,NSTRS
        AC(I)=AC(I)+P(J,I)*S(J)
    6 CONTINUE
   11 CONTINUE
C
      DO 12 I=1,NSTRS
      DO 7 J=1,NSTRS
       DP(I,J)=0.D0
       DP(I,J)=AB(I)*AC(J)
    7 CONTINUE
   12 CONTINUE
C
      DO 13 I=1,NSTRS
      DO 9 J=1,NSTRS
       P1(I,J)=P(I,J)/2.D0/DPHI
       DP(I,J)=DP(I,J)/4.D0/DPHI/DPHI/DPHI
       D2FSIG(I,J)=P1(I,J)-DP(I,J)
    9 CONTINUE
   13 CONTINUE
C-------------------------------------------------------------------
      RETURN
      END