Solve one of the triangular systems l**t* x = b, or l * x = b,
SUBROUTINE DPTTRSV(
TRANS, N, NRHS, D, E, B, LDB, INFO )
CHARACTER
TRANS
INTEGER
INFO, LDB, N, NRHS
DOUBLE
PRECISION D( * )
DOUBLE
PRECISION B( LDB, * ), E( * )
DPTTRSV solves one of the triangular systems
L**T* X = B, or L * X = B,
where L is the Cholesky factor of a Hermitian positive
definite tridiagonal matrix A such that
A = L*D*L**H (computed by DPTTRF).
TRANS (input) CHARACTER
Specifies the form of the system of equations:
= 'N': L * X = B (No transpose)
= 'T': L**T * X = B (Transpose)
N (input) INTEGER
The order of the tridiagonal 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.
D (input) REAL array, dimension (N)
The n diagonal elements of the diagonal matrix D from the factorization computed by DPTTRF.
E (input) COMPLEX array, dimension (N-1)
The (n-1) off-diagonal elements of the unit bidiagonal factor U or L from the factorization computed by DPTTRF (see UPLO).
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