sptsv.f man page

sptsv.f —

Synopsis

Functions/Subroutines

subroutine sptsv (N, NRHS, D, E, B, LDB, INFO)
SPTSV computes the solution to system of linear equations A * X = B for PT matrices

Function/Subroutine Documentation

subroutine sptsv (integerN, integerNRHS, real, dimension( * )D, real, dimension( * )E, real, dimension( ldb, * )B, integerLDB, integerINFO)

SPTSV computes the solution to system of linear equations A * X = B for PT matrices

Purpose:

SPTSV computes the solution to a real system of linear equations
A*X = B, where A is an N-by-N symmetric positive definite tridiagonal
matrix, and X and B are N-by-NRHS matrices.

A is factored as A = L*D*L**T, and the factored form of A is then
used to solve the system of equations.

Parameters:

N

N is INTEGER
The order of the 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 REAL array, dimension (N)
On entry, the n diagonal elements of the tridiagonal matrix
A.  On exit, the n diagonal elements of the diagonal matrix
D from the factorization A = L*D*L**T.

E

E is REAL array, dimension (N-1)
On entry, the (n-1) subdiagonal elements of the tridiagonal
matrix A.  On exit, 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 U**T*D*U factorization of A.)

B

B is REAL array, dimension (LDB,NRHS)
On entry, the N-by-NRHS right hand side matrix B.
On exit, if INFO = 0, the N-by-NRHS solution matrix 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 = -i, the i-th argument had an illegal value
> 0:  if INFO = i, the leading minor of order i is not
      positive definite, and the solution has not been
      computed.  The factorization has not been completed
      unless i = N.

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 115 of file sptsv.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

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

Sat Nov 16 2013 Version 3.4.2 LAPACK