CGETRS(l) ) CGETRS(l)NAME
CGETRS - solve a system of linear equations A * X = B, A**T * X = B, or
A**H * X = B with a general N-by-N matrix A using the LU factorization
computed by CGETRF
SYNOPSIS
SUBROUTINE CGETRS( TRANS, N, NRHS, A, LDA, IPIV, B, LDB, INFO )
CHARACTER TRANS
INTEGER INFO, LDA, LDB, N, NRHS
INTEGER IPIV( * )
COMPLEX A( LDA, * ), B( LDB, * )
PURPOSE
CGETRS solves a system of linear equations A * X = B, A**T * X = B, or
A**H * X = B with a general N-by-N matrix A using the LU factorization
computed by CGETRF.
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.
NRHS (input) INTEGER
The number of right hand sides, i.e., the number of columns of
the matrix B. NRHS >= 0.
A (input) COMPLEX array, dimension (LDA,N)
The factors L and U from the factorization A = P*L*U as com‐
puted by CGETRF.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
IPIV (input) INTEGER array, dimension (N)
The pivot indices from CGETRF; 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
LAPACK version 3.0 15 June 2000 CGETRS(l)
