SUBROUTINE SSILUS (N, NELT, IA, JA, A, ISYM, NL, IL, JL, L, DINV, + NU, IU, JU, U, NROW, NCOL) C .. Scalar Arguments .. INTEGER ISYM, N, NELT, NL, NU C .. Array Arguments .. REAL A(NELT), DINV(N), L(NL), U(NU) INTEGER IA(NELT), IL(NL), IU(NU), JA(NELT), JL(NL), JU(NU), + NCOL(N), NROW(N) C .. Local Scalars .. REAL TEMP INTEGER I, IBGN, ICOL, IEND, INDX, INDX1, INDX2, INDXC1, INDXC2, + INDXR1, INDXR2, IROW, ITEMP, J, JBGN, JEND, JTEMP, K, KC, + KR C***FIRST EXECUTABLE STATEMENT SSILUS C C Count number of elements in each row of the lower triangle. C DO 10 I=1,N NROW(I) = 0 NCOL(I) = 0 10 CONTINUE CVD$R NOCONCUR CVD$R NOVECTOR DO 30 ICOL = 1, N JBGN = JA(ICOL)+1 JEND = JA(ICOL+1)-1 IF( JBGN.LE.JEND ) THEN DO 20 J = JBGN, JEND IF( IA(J).LT.ICOL ) THEN NCOL(ICOL) = NCOL(ICOL) + 1 ELSE NROW(IA(J)) = NROW(IA(J)) + 1 IF( ISYM.NE.0 ) NCOL(IA(J)) = NCOL(IA(J)) + 1 ENDIF 20 CONTINUE ENDIF 30 CONTINUE JU(1) = 1 IL(1) = 1 DO 40 ICOL = 1, N IL(ICOL+1) = IL(ICOL) + NROW(ICOL) JU(ICOL+1) = JU(ICOL) + NCOL(ICOL) NROW(ICOL) = IL(ICOL) NCOL(ICOL) = JU(ICOL) 40 CONTINUE C C Copy the matrix A into the L and U structures. DO 60 ICOL = 1, N DINV(ICOL) = A(JA(ICOL)) JBGN = JA(ICOL)+1 JEND = JA(ICOL+1)-1 IF( JBGN.LE.JEND ) THEN DO 50 J = JBGN, JEND IROW = IA(J) IF( IROW.LT.ICOL ) THEN C Part of the upper triangle. IU(NCOL(ICOL)) = IROW U(NCOL(ICOL)) = A(J) NCOL(ICOL) = NCOL(ICOL) + 1 ELSE C Part of the lower triangle (stored by row). JL(NROW(IROW)) = ICOL L(NROW(IROW)) = A(J) NROW(IROW) = NROW(IROW) + 1 IF( ISYM.NE.0 ) THEN C Symmetric...Copy lower triangle into upper triangle as well. IU(NCOL(IROW)) = ICOL U(NCOL(IROW)) = A(J) NCOL(IROW) = NCOL(IROW) + 1 ENDIF ENDIF 50 CONTINUE ENDIF 60 CONTINUE C C Sort the rows of L and the columns of U. DO 110 K = 2, N JBGN = JU(K) JEND = JU(K+1)-1 IF( JBGN.LT.JEND ) THEN DO 80 J = JBGN, JEND-1 DO 70 I = J+1, JEND IF( IU(J).GT.IU(I) ) THEN ITEMP = IU(J) IU(J) = IU(I) IU(I) = ITEMP TEMP = U(J) U(J) = U(I) U(I) = TEMP ENDIF 70 CONTINUE 80 CONTINUE ENDIF IBGN = IL(K) IEND = IL(K+1)-1 IF( IBGN.LT.IEND ) THEN DO 100 I = IBGN, IEND-1 DO 90 J = I+1, IEND IF( JL(I).GT.JL(J) ) THEN JTEMP = JU(I) JU(I) = JU(J) JU(J) = JTEMP TEMP = L(I) L(I) = L(J) L(J) = TEMP ENDIF 90 CONTINUE 100 CONTINUE ENDIF 110 CONTINUE C C Perform the incomplete LDU decomposition. DO 300 I=2,N C C I-th row of L INDX1 = IL(I) INDX2 = IL(I+1) - 1 IF(INDX1 .GT. INDX2) GO TO 200 DO 190 INDX=INDX1,INDX2 IF(INDX .EQ. INDX1) GO TO 180 INDXR1 = INDX1 INDXR2 = INDX - 1 INDXC1 = JU(JL(INDX)) INDXC2 = JU(JL(INDX)+1) - 1 IF(INDXC1 .GT. INDXC2) GO TO 180 160 KR = JL(INDXR1) 170 KC = IU(INDXC1) IF(KR .GT. KC) THEN INDXC1 = INDXC1 + 1 IF(INDXC1 .LE. INDXC2) GO TO 170 ELSEIF(KR .LT. KC) THEN INDXR1 = INDXR1 + 1 IF(INDXR1 .LE. INDXR2) GO TO 160 ELSEIF(KR .EQ. KC) THEN L(INDX) = L(INDX) - L(INDXR1)*DINV(KC)*U(INDXC1) INDXR1 = INDXR1 + 1 INDXC1 = INDXC1 + 1 IF(INDXR1 .LE. INDXR2 .AND. INDXC1 .LE. INDXC2) GO TO 160 ENDIF 180 L(INDX) = L(INDX)/DINV(JL(INDX)) 190 CONTINUE C C I-th column of U 200 INDX1 = JU(I) INDX2 = JU(I+1) - 1 IF(INDX1 .GT. INDX2) GO TO 260 DO 250 INDX=INDX1,INDX2 IF(INDX .EQ. INDX1) GO TO 240 INDXC1 = INDX1 INDXC2 = INDX - 1 INDXR1 = IL(IU(INDX)) INDXR2 = IL(IU(INDX)+1) - 1 IF(INDXR1 .GT. INDXR2) GO TO 240 210 KR = JL(INDXR1) 220 KC = IU(INDXC1) IF(KR .GT. KC) THEN INDXC1 = INDXC1 + 1 IF(INDXC1 .LE. INDXC2) GO TO 220 ELSEIF(KR .LT. KC) THEN INDXR1 = INDXR1 + 1 IF(INDXR1 .LE. INDXR2) GO TO 210 ELSEIF(KR .EQ. KC) THEN U(INDX) = U(INDX) - L(INDXR1)*DINV(KC)*U(INDXC1) INDXR1 = INDXR1 + 1 INDXC1 = INDXC1 + 1 IF(INDXR1 .LE. INDXR2 .AND. INDXC1 .LE. INDXC2) GO TO 210 ENDIF 240 U(INDX) = U(INDX)/DINV(IU(INDX)) 250 CONTINUE C C I-th diagonal element 260 INDXR1 = IL(I) INDXR2 = IL(I+1) - 1 IF(INDXR1 .GT. INDXR2) GO TO 300 INDXC1 = JU(I) INDXC2 = JU(I+1) - 1 IF(INDXC1 .GT. INDXC2) GO TO 300 270 KR = JL(INDXR1) 280 KC = IU(INDXC1) IF(KR .GT. KC) THEN INDXC1 = INDXC1 + 1 IF(INDXC1 .LE. INDXC2) GO TO 280 ELSEIF(KR .LT. KC) THEN INDXR1 = INDXR1 + 1 IF(INDXR1 .LE. INDXR2) GO TO 270 ELSEIF(KR .EQ. KC) THEN DINV(I) = DINV(I) - L(INDXR1)*DINV(KC)*U(INDXC1) INDXR1 = INDXR1 + 1 INDXC1 = INDXC1 + 1 IF(INDXR1 .LE. INDXR2 .AND. INDXC1 .LE. INDXC2) GO TO 270 ENDIF C 300 CONTINUE C C Replace diagonal elements by their inverses. CVD$ VECTOR DO 430 I=1,N DINV(I) = 1.0E0/DINV(I) 430 CONTINUE C RETURN C------------- LAST LINE OF SSILUS FOLLOWS ---------------------------- END