DOUBLE PRECISION FUNCTION DNRM2 ( N, DX, INCX)
      INTEGER          N, INCX, NEXT
      DOUBLE PRECISION DX( * ), CUTLO, CUTHI, HITEST, SUM,
     *                 XMAX, ZERO, ONE
      INTRINSIC        ABS, SQRT
      INTEGER          I, J, NN
      PARAMETER ( ZERO = 0.0D+0, ONE = 1.0D+0 )
C
C     EUCLIDEAN NORM OF THE N-VECTOR STORED IN DX() WITH STORAGE
C     INCREMENT INCX .
C     IF    N .LE. 0 RETURN WITH RESULT = 0.
C     IF N .GE. 1 THEN INCX MUST BE .GE. 1
C
C           C.L.LAWSON, 1978 JAN 08
C
C     FOUR PHASE METHOD     USING TWO BUILT-IN CONSTANTS THAT ARE
C     HOPEFULLY APPLICABLE TO ALL MACHINES.
C         CUTLO = MAXIMUM OF  DSQRT(U/EPS)  OVER ALL KNOWN MACHINES.
C         CUTHI = MINIMUM OF  DSQRT(V)      OVER ALL KNOWN MACHINES.
C     WHERE
C         EPS = SMALLEST NO. SUCH THAT EPS + 1. .GT. 1.
C         U   = SMALLEST POSITIVE NO.   (UNDERFLOW LIMIT)
C         V   = LARGEST  NO.            (OVERFLOW  LIMIT)
C
C     BRIEF OUTLINE OF ALGORITHM..
C
C     PHASE 1    SCANS ZERO COMPONENTS.
C     MOVE TO PHASE 2 WHEN A COMPONENT IS NONZERO AND .LE. CUTLO
C     MOVE TO PHASE 3 WHEN A COMPONENT IS .GT. CUTLO
C     MOVE TO PHASE 4 WHEN A COMPONENT IS .GE. CUTHI/M
C     WHERE M = N FOR X() REAL AND M = 2*N FOR COMPLEX.
C
C     VALUES FOR CUTLO AND CUTHI..
C     FROM THE ENVIRONMENTAL PARAMETERS LISTED IN THE IMSL CONVERTER
C     DOCUMENT THE LIMITING VALUES ARE AS FOLLOWS..
C     CUTLO, S.P.   U/EPS = 2**(-102) FOR  HONEYWELL.  CLOSE SECONDS ARE
C                   UNIVAC AND DEC AT 2**(-103)
C                   THUS CUTLO = 2**(-51) = 4.44089E-16
C     CUTHI, S.P.   V = 2**127 FOR UNIVAC, HONEYWELL, AND DEC.
C                   THUS CUTHI = 2**(63.5) = 1.30438E19
C     CUTLO, D.P.   U/EPS = 2**(-67) FOR HONEYWELL AND DEC.
C                   THUS CUTLO = 2**(-33.5) = 8.23181D-11
C     CUTHI, D.P.   SAME AS S.P.  CUTHI = 1.30438D19
      DATA CUTLO, CUTHI / 8.232D-11,  1.304D19 /
C
      IF ( N .LE. 0) THEN
         DNRM2  = ZERO
      ELSE
         NEXT = 1
         SUM  = ZERO
         NN   = N * INCX
C
C  BEGIN MAIN LOOP
C
         I = 1
   20    CONTINUE
         GO TO ( 30, 50, 70, 110 ), NEXT
   30    CONTINUE
         IF( ABS( DX( I ) ) .GT. CUTLO ) GO TO 85
         NEXT = 2
         XMAX = ZERO
C
C  PHASE 1.  SUM IS ZERO
C
   50    CONTINUE
         IF ( DX( I ) .EQ. ZERO ) GO TO 200
         IF ( ABS( DX( I ) ) .GT. CUTLO ) GO TO 85
C
C  PREPARE FOR PHASE 2.
C
         NEXT = 3
         GO TO 105
C
C  PREPARE FOR PHASE 4.
C
  100    CONTINUE
         I    = J
         NEXT = 4
         SUM  = ( SUM / DX( I ) ) / DX( I )
  105    CONTINUE
         XMAX = ABS( DX( I ) )
         SUM  = SUM + ( DX( I ) / XMAX ) ** 2
         GO TO 200
C
C  PHASE 2.  SUM IS SMALL. SCALE TO AVOID DESTRUCTIVE UNDERFLOW.
C
   70    CONTINUE
         IF ( ABS( DX( I ) ) .GT. CUTLO ) THEN
C
C  PREPARE FOR PHASE 3.
C
            SUM = ( SUM * XMAX) * XMAX
            GO TO 85
         END IF
C
C  COMMON CODE FOR PHASES 2 AND 4.
C  IN PHASE 4 SUM IS LARGE.  SCALE TO AVOID OVERFLOW.
C
  110    CONTINUE
         IF ( ABS( DX( I ) ) .GT. XMAX ) THEN
            SUM  = ONE + SUM * ( XMAX / DX( I ) ) ** 2
            XMAX = ABS( DX( I ) )
         ELSE
            SUM = SUM + ( DX( I ) / XMAX ) ** 2
         END IF
  200    CONTINUE
         I = I + INCX
         IF ( I .LE. NN ) GO TO 20
C
C  END OF MAIN LOOP.
C
C  COMPUTE SQUARE ROOT AND ADJUST FOR SCALING.
C
CS       SNRM2 = XMAX * SQRT(SUM)
CD       DNRM2 = XMAX * SQRT(SUM)
         GO TO 300
C
C  FOR REAL OR D.P. SET HITEST = CUTHI/N
C
   85    CONTINUE
         HITEST = CUTHI/FLOAT( N )
C
C  PHASE 3. SUM IS MID-RANGE.  NO SCALING.
C
         DO 95 J = I, NN, INCX
            IF( ABS( DX( J ) ) .GE. HITEST ) GO TO 100
            SUM = SUM + DX( J ) ** 2
   95    CONTINUE
         DNRM2 = SQRT( SUM )
      END IF
  300 CONTINUE
      RETURN
      END
      DOUBLE PRECISION FUNCTION DMACH(JOB)
      INTEGER JOB
C
C     SMACH COMPUTES MACHINE PARAMETERS OF FLOATING POINT
C     ARITHMETIC FOR USE IN TESTING ONLY.  NOT REQUIRED BY
C     LINPACK PROPER.
C
C     IF TROUBLE WITH AUTOMATIC COMPUTATION OF THESE QUANTITIES,
C     THEY CAN BE SET BY DIRECT ASSIGNMENT STATEMENTS.
C     ASSUME THE COMPUTER HAS
C
C        B = BASE OF ARITHMETIC
C        T = NUMBER OF BASE  B  DIGITS
C        L = SMALLEST POSSIBLE EXPONENT
C        U = LARGEST POSSIBLE EXPONENT
C
C     THEN
C
C        EPS = B**(1-T)
C        TINY = 100.0*B**(-L+T)
C        HUGE = 0.01*B**(U-T)
C
C     DMACH SAME AS SMACH EXCEPT T, L, U APPLY TO
C     DOUBLE PRECISION.
C
C     CMACH SAME AS SMACH EXCEPT IF COMPLEX DIVISION
C     IS DONE BY
C
C        1/(X+I*Y) = (X-I*Y)/(X**2+Y**2)
C
C     THEN
C
C        TINY = SQRT(TINY)
C        HUGE = SQRT(HUGE)
C
C
C     JOB IS 1, 2 OR 3 FOR EPSILON, TINY AND HUGE, RESPECTIVELY.
C
      DOUBLE PRECISION EPS,TINY,HUGE,S
C
      EPS = 1.0D0
   10 EPS = EPS/2.0D0
      S = 1.0D0 + EPS
      IF (S .GT. 1.0D0) GO TO 10
      EPS = 2.0D0*EPS
C
      S = 1.0D0
   20 TINY = S
      S = S/16.0D0
      IF (S*1.0d0 .NE. 0.0D0) GO TO 20
      TINY = (TINY/EPS)*100.0
      HUGE = 1.0D0/TINY
C
      IF (JOB .EQ. 1) DMACH = EPS
      IF (JOB .EQ. 2) DMACH = TINY
      IF (JOB .EQ. 3) DMACH = HUGE
      RETURN
      END
      SUBROUTINE  DCOPY(N,DX,INCX,DY,INCY)
C
C     COPIES A VECTOR, X, TO A VECTOR, Y.
C     USES UNROLLED LOOPS FOR INCREMENTS EQUAL TO ONE.
C     JACK DONGARRA, LINPACK, 3/11/78.
C
      DOUBLE PRECISION DX(1),DY(1)
      INTEGER I,INCX,INCY,IX,IY,M,MP1,N
C
      IF(N.LE.0)RETURN
      IF(INCX.EQ.1.AND.INCY.EQ.1)GO TO 20
C
C        CODE FOR UNEQUAL INCREMENTS OR EQUAL INCREMENTS
C          NOT EQUAL TO 1
C
      IX = 1
      IY = 1
      IF(INCX.LT.0)IX = (-N+1)*INCX + 1
      IF(INCY.LT.0)IY = (-N+1)*INCY + 1
      DO 10 I = 1,N
        DY(IY) = DX(IX)
        IX = IX + INCX
        IY = IY + INCY
   10 CONTINUE
      RETURN
C
C        CODE FOR BOTH INCREMENTS EQUAL TO 1
C
C
C        CLEAN-UP LOOP
C
   20 M = MOD(N,7)
      IF( M .EQ. 0 ) GO TO 40
      DO 30 I = 1,M
        DY(I) = DX(I)
   30 CONTINUE
      IF( N .LT. 7 ) RETURN
   40 MP1 = M + 1
      DO 50 I = MP1,N,7
        DY(I) = DX(I)
        DY(I + 1) = DX(I + 1)
        DY(I + 2) = DX(I + 2)
        DY(I + 3) = DX(I + 3)
        DY(I + 4) = DX(I + 4)
        DY(I + 5) = DX(I + 5)
        DY(I + 6) = DX(I + 6)
   50 CONTINUE
      RETURN
      END
      DOUBLE PRECISION FUNCTION DDOT(N,DX,INCX,DY,INCY)
C
C     FORMS THE DOT PRODUCT OF TWO VECTORS.
C     USES UNROLLED LOOPS FOR INCREMENTS EQUAL TO ONE.
C     JACK DONGARRA, LINPACK, 3/11/78.
C
      DOUBLE PRECISION DX(1),DY(1),DTEMP
      INTEGER I,INCX,INCY,IX,IY,M,MP1,N
C
      DDOT = 0.0D0
      DTEMP = 0.0D0
      IF(N.LE.0)RETURN
      IF(INCX.EQ.1.AND.INCY.EQ.1)GO TO 20
C
C        CODE FOR UNEQUAL INCREMENTS OR EQUAL INCREMENTS
C          NOT EQUAL TO 1
C
      IX = 1
      IY = 1
      IF(INCX.LT.0)IX = (-N+1)*INCX + 1
      IF(INCY.LT.0)IY = (-N+1)*INCY + 1
      DO 10 I = 1,N
        DTEMP = DTEMP + DX(IX)*DY(IY)
        IX = IX + INCX
        IY = IY + INCY
   10 CONTINUE
      DDOT = DTEMP
      RETURN
C
C        CODE FOR BOTH INCREMENTS EQUAL TO 1
C
C
C        CLEAN-UP LOOP
C
   20 M = MOD(N,5)
      IF( M .EQ. 0 ) GO TO 40
      DO 30 I = 1,M
        DTEMP = DTEMP + DX(I)*DY(I)
   30 CONTINUE
      IF( N .LT. 5 ) GO TO 60
   40 MP1 = M + 1
      DO 50 I = MP1,N,5
        DTEMP = DTEMP + DX(I)*DY(I) + DX(I + 1)*DY(I + 1) +
     *   DX(I + 2)*DY(I + 2) + DX(I + 3)*DY(I + 3) + DX(I + 4)*DY(I + 4)
   50 CONTINUE
   60 DDOT = DTEMP
      RETURN
      END
      SUBROUTINE  DSCAL(N,DA,DX,INCX)
C
C     SCALES A VECTOR BY A CONSTANT.
C     USES UNROLLED LOOPS FOR INCREMENT EQUAL TO ONE.
C     JACK DONGARRA, LINPACK, 3/11/78.
C
      DOUBLE PRECISION DA,DX(1)
      INTEGER I,INCX,M,MP1,N,NINCX
C
      IF(N.LE.0)RETURN
      IF(INCX.EQ.1)GO TO 20
C
C        CODE FOR INCREMENT NOT EQUAL TO 1
C
      NINCX = N*INCX
      DO 10 I = 1,NINCX,INCX
        DX(I) = DA*DX(I)
   10 CONTINUE
      RETURN
C
C        CODE FOR INCREMENT EQUAL TO 1
C
C
C        CLEAN-UP LOOP
C
   20 M = MOD(N,5)
      IF( M .EQ. 0 ) GO TO 40
      DO 30 I = 1,M
        DX(I) = DA*DX(I)
   30 CONTINUE
      IF( N .LT. 5 ) RETURN
   40 MP1 = M + 1
      DO 50 I = MP1,N,5
        DX(I) = DA*DX(I)
        DX(I + 1) = DA*DX(I + 1)
        DX(I + 2) = DA*DX(I + 2)
        DX(I + 3) = DA*DX(I + 3)
        DX(I + 4) = DA*DX(I + 4)
   50 CONTINUE
      RETURN
      END
      SUBROUTINE DAXPY(N,DA,DX,INCX,DY,INCY)
C
C     CONSTANT TIMES A VECTOR PLUS A VECTOR.
C     USES UNROLLED LOOPS FOR INCREMENTS EQUAL TO ONE.
C     JACK DONGARRA, LINPACK, 3/11/78.
C
      DOUBLE PRECISION DX(1),DY(1),DA
      INTEGER I,INCX,INCY,M,MP1,N,IX,IY
C
      IF(N.LE.0)RETURN
      IF (DA .EQ. 0.0D0) RETURN
      IF(INCX.EQ.1.AND.INCY.EQ.1)GO TO 20
C
C        CODE FOR UNEQUAL INCREMENTS OR EQUAL INCREMENTS
C          NOT EQUAL TO 1
C
      IX = 1
      IY = 1
      IF(INCX.LT.0)IX = (-N+1)*INCX + 1
      IF(INCY.LT.0)IY = (-N+1)*INCY + 1
      DO 10 I = 1,N
        DY(IY) = DY(IY) + DA*DX(IX)
        IX = IX + INCX
        IY = IY + INCY
   10 CONTINUE
      RETURN
C
C        CODE FOR BOTH INCREMENTS EQUAL TO 1
C
C
C        CLEAN-UP LOOP
C
   20 M = MOD(N,4)
      IF( M .EQ. 0 ) GO TO 40
      DO 30 I = 1,M
        DY(I) = DY(I) + DA*DX(I)
   30 CONTINUE
      IF( N .LT. 4 ) RETURN
   40 MP1 = M + 1
      DO 50 I = MP1,N,4
        DY(I) = DY(I) + DA*DX(I)
        DY(I + 1) = DY(I + 1) + DA*DX(I + 1)
        DY(I + 2) = DY(I + 2) + DA*DX(I + 2)
        DY(I + 3) = DY(I + 3) + DA*DX(I + 3)
   50 CONTINUE
      RETURN
      END

.