CDTTRSV ‐ solve one of the systems of equations L * X = B, L**T *
X = B, or L**H * X = B, SUBROUTINE CDTTRSV( UPLO, TRANS, N, NRHS,
DL, D, DU, B, LDB, INFO )
CHARACTER UPLO, TRANS
INTEGER INFO, LDB, N, NRHS
COMPLEX B( LDB, * ), D( * ), DL( * ), DU( * ) CDTTRSV solves
one of the systems of equations L * X = B, L**T * X = B, or L**H
* X = B, U * X = B, U**T * X = B, or U**H * X = B,
with factors of the tridiagonal matrix A from the LU factoriza‐
tion computed by CDTTRF.UPLO (input) CHARACTER*1 Specifies whether to solve with L or
U. TRANS (input) CHARACTER Specifies the form of the system ofequations:
= ’N’: A * X = B (No transpose)
= ’T’: A**T * X = B (Transpose)
= ’C’: A**H * X = B (Conjugate transpose) N (input) INTE‐
GER 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. DL (input) COMPLEX array, dimen‐
sion (N‐1) The (n‐1) multipliers that define the matrix L from
the LU factorization of A. D (input) COMPLEX array, dimen‐
sion (N) The n diagonal elements of the upper triangular matrix Ufrom the LU factorization of A. DU (input) COMPLEX array,
dimension (N‐1) The (n‐1) elements of the first superdiagonal of
U. B (input/output) COMPLEX array, dimension (LDB,NRHS) On
entry, the right hand side matrix B. On exit, B is overwritten
by the solution matrix X. LDB (input) INTEGER The leading
dimension of the array B. LDB >= max(1,N). INFO (output) IN‐
TEGER = 0: successful exit
< 0: if INFO = ‐i, the i‐th argument had an illegal value