SGESL(3F)

NAME
     SGESL   - SGESL solves the real system A * X = B  or  TRANS(A) * X = B
     using the factors computed by SGECO or SGEFA.


SYNOPSYS
      SUBROUTINE SGESL(A,LDA,N,IPVT,B,JOB)

DESCRIPTION
     On Entry

     A REAL(LDA, N)
        the output from SGECO or SGEFA.

     LDA INTEGER
        the leading dimension of the array  A .

     N INTEGER
        the order of the matrix  A .

     IPVT INTEGER(N)
        the pivot vector from SGECO or SGEFA.

     B REAL(N)
        the right hand side vector.

     JOB INTEGER
        = 0         to solve  A*X = B ,
        = nonzero   to solve  TRANS(A)*X = B  where
        TRANS(A)  is the transpose.  On Return

     B the solution vector  X . Error Condition

     A division by zero will occur if the input factor contains a zero on the
     diagonal.  Technically, this indicates singularity, but it is often
     caused by improper arguments or improper setting of LDA .  It will not
     occur if the subroutines are called correctly and if SGECO has set RCOND
     .GT. 0.0 or SGEFA has set INFO .EQ. 0 .  To compute  INVERSE(A) * C
     where  C  is a matrix with  P  columns
        CALL SGECO(A,LDA,N,IPVT,RCOND,Z)
        IF (RCOND is too small) GO TO ...
        DO 10 J = 1, P
        CALL SGESL(A,LDA,N,IPVT,C(1,J),0) 10 CONTINUE LINPACK.  This version
     dated 08/14/78 .  Cleve Moler, University of New Mexico, Argonne National
     Lab.  Subroutines and Functions BLAS SAXPY,SDOT