- SUBROUTINE SDTTRSV(
- UPLO, TRANS, N, NRHS, DL, D, DU, B, LDB, INFO )
- CHARACTER UPLO, TRANS
- INTEGER INFO, LDB, N, NRHS
- REAL B( LDB, * ), D( * ), DL( * ), DU( * )
PURPOSESDTTRSV 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 factorization computed by SDTTRF.
- UPLO (input) CHARACTER*1
- Specifies whether to solve with L or U.
- TRANS (input) CHARACTER
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.
- DL (input) COMPLEX array, dimension (N-1)
- The (n-1) multipliers that define the matrix L from the LU factorization of A.
- D (input) COMPLEX array, dimension (N)
- The n diagonal elements of the upper triangular matrix U from 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) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value