
CGBTRS(l) ) CGBTRS(l)
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 trans
pose)
= '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 ith argument had an illegal value
LAPACK version 3.0 15 June 2000 CGBTRS(l) 
