subroutine zpttrs (UPLO, N, NRHS, D, E, B, LDB, INFO)
subroutine zpttrs (characterUPLO, integerN, integerNRHS, double precision, dimension( * )D, complex*16, dimension( * )E, complex*16, dimension( ldb, * )B, integerLDB, integerINFO)ZPTTRS Purpose:
ZPTTRS solves a tridiagonal system of the form A * X = B using the factorization A = U**H *D* U or A = L*D*L**H computed by ZPTTRF. D is a diagonal matrix specified in the vector D, U (or L) is a unit bidiagonal matrix whose superdiagonal (subdiagonal) is specified in the vector E, and X and B are N by NRHS matrices.
UPLO is CHARACTER*1 Specifies the form of the factorization and whether the vector E is the superdiagonal of the upper bidiagonal factor U or the subdiagonal of the lower bidiagonal factor L. = 'U': A = U**H *D*U, E is the superdiagonal of U = 'L': A = L*D*L**H, E is the subdiagonal of LN
N is INTEGER The order of the tridiagonal matrix A. N >= 0.NRHS
NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.D
D is DOUBLE PRECISION array, dimension (N) The n diagonal elements of the diagonal matrix D from the factorization A = U**H *D*U or A = L*D*L**H.E
E is COMPLEX*16 array, dimension (N-1) If UPLO = 'U', the (n-1) superdiagonal elements of the unit bidiagonal factor U from the factorization A = U**H*D*U. If UPLO = 'L', the (n-1) subdiagonal elements of the unit bidiagonal factor L from the factorization A = L*D*L**H.B
B is DOUBLE PRECISION array, dimension (LDB,NRHS) On entry, the right hand side vectors B for the system of linear equations. On exit, the solution vectors, X.LDB
LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N).INFO
INFO is INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value
Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd.Date:
September 2012Definition at line 122 of file zpttrs.f.