dpttrs.f man page

dpttrs.f —

Synopsis

Functions/Subroutines

subroutine dpttrs (N, NRHS, D, E, B, LDB, INFO)
DPTTRS

Function/Subroutine Documentation

subroutine dpttrs (integerN, integerNRHS, double precision, dimension( * )D, double precision, dimension( * )E, double precision, dimension( ldb, * )B, integerLDB, integerINFO)

DPTTRS

Purpose:

DPTTRS 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).

INFO

INFO is INTEGER
= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal value

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 110 of file dpttrs.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

dpttrs(3) is an alias of dpttrs.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK