dptts2.f3
Usage
Functions/Subroutines
subroutine dptts2 (n, nrhs, d, e, b, ldb)
DPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf.
Function/Subroutine Documentation
subroutine dptts2 (integer n, integer nrhs, double precision, dimension( * ) d, double precision, dimension( * ) e, double precision, dimension( ldb, * ) b, integer ldb)
DPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf.
Purpose:
!> !> DPTTS2 solves a tridiagonal system of the form !> A * X = B !> using the L*D*L**T factorization of A computed by DPTTRF. D is a !> diagonal matrix specified in the vector D, L is a unit bidiagonal !> matrix whose subdiagonal is specified in the vector E, and X and B !> are N by NRHS matrices. !>
Parameters
N
!> 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 !> L*D*L**T factorization of A. !>
E
!> E is DOUBLE PRECISION array, dimension (N-1) !> The (n-1) subdiagonal elements of the unit bidiagonal factor !> L from the L*D*L**T factorization of A. E can also be regarded !> as the superdiagonal of the unit bidiagonal factor U from the !> factorization A = U**T*D*U. !>
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). !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 101 of file dptts2.f.
Releases
4 releases since Debian 7 (Wheezy); the text changed 3 times.