cgbtrs(3F)

NAME
     CGBTRS - solve a system of linear equations  A * X = B, A**T * X = B, or
     A**H * X = B with a general band matrix A using the LU factorization
     computed by CGBTRF

SYNOPSIS
     SUBROUTINE CGBTRS( TRANS, N, KL, KU, NRHS, AB, LDAB, IPIV, B, LDB, INFO )

         CHARACTER      TRANS

         INTEGER        INFO, KL, KU, LDAB, LDB, N, NRHS

         INTEGER        IPIV( * )

         COMPLEX        AB( LDAB, * ), B( LDB, * )

PURPOSE
     CGBTRS solves a system of linear equations
        A * X = B,  A**T * X = B,  or  A**H * X = B with a general band matrix
     A using the LU factorization computed by CGBTRF.


ARGUMENTS
     TRANS   (input) CHARACTER*1
             Specifies the form of the system of equations.  = 'N':  A * X = B
             (No transpose)
             = 'T':  A**T * X = B  (Transpose)
             = 'C':  A**H * X = B  (Conjugate transpose)

     N       (input) INTEGER
             The order of the matrix A.  N >= 0.

     KL      (input) INTEGER
             The number of subdiagonals within the band of A.  KL >= 0.

     KU      (input) INTEGER
             The number of superdiagonals within the band of A.  KU >= 0.

     NRHS    (input) INTEGER
             The number of right hand sides, i.e., the number of columns of
             the matrix B.  NRHS >= 0.

     AB      (input) COMPLEX array, dimension (LDAB,N)
             Details of the LU factorization of the band matrix A, as computed
             by CGBTRF.  U is stored as an upper triangular band matrix with
             KL+KU superdiagonals in rows 1 to KL+KU+1, and the multipliers
             used during the factorization are stored in rows KL+KU+2 to
             2*KL+KU+1.

     LDAB    (input) INTEGER
             The leading dimension of the array AB.  LDAB >= 2*KL+KU+1.
     IPIV    (input) INTEGER array, dimension (N)
             The pivot indices; for 1 <= i <= N, row i of the matrix was
             interchanged with row IPIV(i).

     B       (input/output) COMPLEX array, dimension (LDB,NRHS)
             On entry, the right hand side matrix B.  On exit, the solution
             matrix X.

     LDB     (input) INTEGER
             The leading dimension of the array B.  LDB >= max(1,N).

     INFO    (output) INTEGER
             = 0:  successful exit
             < 0:  if INFO = -i, the i-th argument had an illegal value