SLATEC Routines --- SNBSL ---

*DECK SNBSL
      SUBROUTINE SNBSL (ABE, LDA, N, ML, MU, IPVT, B, JOB)
C***BEGIN PROLOGUE  SNBSL
C***PURPOSE  Solve a real band system using the factors computed by
C            SNBCO or SNBFA.
C***LIBRARY   SLATEC
C***CATEGORY  D2A2
C***TYPE      SINGLE PRECISION (SNBSL-S, DNBSL-D, CNBSL-C)
C***KEYWORDS  BANDED, LINEAR EQUATIONS, NONSYMMETRIC, SOLVE
C***AUTHOR  Voorhees, E. A., (LANL)
C***DESCRIPTION
C
C     SNBSL solves the real band system
C     A * X = B  or  TRANS(A) * X = B
C     using the factors computed by SNBCO or SNBFA.
C
C     On Entry
C
C        ABE     REAL(LDA, NC)
C                the output from SNBCO or SNBFA.
C                NC must be .GE. 2*ML+MU+1 .
C
C        LDA     INTEGER
C                the leading dimension of the array  ABE .
C
C        N       INTEGER
C                the order of the original matrix.
C
C        ML      INTEGER
C                number of diagonals below the main diagonal.
C
C        MU      INTEGER
C                number of diagonals above the main diagonal.
C
C        IPVT    INTEGER(N)
C                the pivot vector from SNBCO or SNBFA.
C
C        B       REAL(N)
C                the right hand side vector.
C
C        JOB     INTEGER
C                = 0         to solve  A*X = B .
C                = nonzero   to solve  TRANS(A)*X = B , where
C                            TRANS(A)  is the transpose.
C
C     On Return
C
C        B       the solution vector  X .
C
C     Error Condition
C
C        A division by zero will occur if the input factor contains a
C        zero on the diagonal.  Technically, this indicates singularity,
C        but it is often caused by improper arguments or improper
C        setting of LDA.  It will not occur if the subroutines are
C        called correctly and if SNBCO has set RCOND .GT. 0.0
C        or SNBFA has set INFO .EQ. 0 .
C
C     To compute  INVERSE(A) * C  where  C  is a matrix
C     with  P  columns
C           CALL SNBCO(ABE,LDA,N,ML,MU,IPVT,RCOND,Z)
C           IF (RCOND is too small) GO TO ...
C           DO 10 J = 1, P
C             CALL SNBSL(ABE,LDA,N,ML,MU,IPVT,C(1,J),0)
C        10 CONTINUE
C
C***REFERENCES  J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W.
C                 Stewart, LINPACK Users' Guide, SIAM, 1979.
C***ROUTINES CALLED  SAXPY, SDOT
C***REVISION HISTORY  (YYMMDD)
C   800717  DATE WRITTEN
C   890531  Changed all specific intrinsics to generic.  (WRB)
C   890831  Modified array declarations.  (WRB)
C   890831  REVISION DATE from Version 3.2
C   891214  Prologue converted to Version 4.0 format.  (BAB)
C   920501  Reformatted the REFERENCES section.  (WRB)
C***END PROLOGUE  SNBSL