dgetrs (l)  Linux Manuals
dgetrs: solves a system of linear equations A * X = B or Aaq * X = B with a general NbyN matrix A using the LU factorization computed by DGETRF
NAME
DGETRS  solves a system of linear equations A * X = B or Aaq * X = B with a general NbyN matrix A using the LU factorization computed by DGETRFSYNOPSIS
 SUBROUTINE DGETRS(
 TRANS, N, NRHS, A, LDA, IPIV, B, LDB, INFO )
 CHARACTER TRANS
 INTEGER INFO, LDA, LDB, N, NRHS
 INTEGER IPIV( * )
 DOUBLE PRECISION A( LDA, * ), B( LDB, * )
PURPOSE
DGETRS solves a system of linear equationsA
ARGUMENTS
 TRANS (input) CHARACTER*1

Specifies the form of the system of equations:
= aqNaq: A * X = B (No transpose)
= aqTaq: Aaq* X = B (Transpose)
= aqCaq: Aaq* X = B (Conjugate transpose = 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) DOUBLE PRECISION array, dimension (LDA,N)
 The factors L and U from the factorization A = P*L*U as computed by DGETRF.
 LDA (input) INTEGER
 The leading dimension of the array A. LDA >= max(1,N).
 IPIV (input) INTEGER array, dimension (N)
 The pivot indices from DGETRF; for 1<=i<=N, row i of the matrix was interchanged with row IPIV(i).
 B (input/output) DOUBLE PRECISION 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