man dgetrs (Fonctions bibliothèques) - solve a system of linear equations A * X = B or A' * X = B with a general N-by-N matrix A using the LU factorization computed by DGETRF

NAME

DGETRS - solve a system of linear equations A * X = B or A' * X = B with a general N-by-N matrix A using the LU factorization computed by DGETRF

DGETRS solves a system of linear equations A * X = B or A' * X = B with a general N-by-N matrix A using the LU factorization computed by DGETRF.

TRANS (input) CHARACTER*1: Specifies the form of the system of equations:

= 'N': A * X = B (No transpose)

= 'T': A'* X = B (Transpose)

= 'C': A'* 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 i-th argument had an illegal value