dgttrs.f man page

dgttrs.f —

Synopsis

Functions/Subroutines

subroutine dgttrs (TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB, INFO)
DGTTRS

Function/Subroutine Documentation

subroutine dgttrs (characterTRANS, integerN, integerNRHS, double precision, dimension( * )DL, double precision, dimension( * )D, double precision, dimension( * )DU, double precision, dimension( * )DU2, integer, dimension( * )IPIV, double precision, dimension( ldb, * )B, integerLDB, integerINFO)

DGTTRS

Purpose:

DGTTRS solves one of the systems of equations
   A*X = B  or  A**T*X = B,
with a tridiagonal matrix A using the LU factorization computed
by DGTTRF.

Parameters:

TRANS

TRANS is CHARACTER*1
Specifies the form of the system of equations.
= 'N':  A * X = B  (No transpose)
= 'T':  A**T* X = B  (Transpose)
= 'C':  A**T* X = B  (Conjugate transpose = Transpose)

N

N is INTEGER
The order of the matrix A.

NRHS

NRHS is INTEGER
The number of right hand sides, i.e., the number of columns
of the matrix B.  NRHS >= 0.

DL

DL is DOUBLE PRECISION array, dimension (N-1)
The (n-1) multipliers that define the matrix L from the
LU factorization of A.

D

D is DOUBLE PRECISION array, dimension (N)
The n diagonal elements of the upper triangular matrix U from
the LU factorization of A.

DU

DU is DOUBLE PRECISION array, dimension (N-1)
The (n-1) elements of the first super-diagonal of U.

DU2

DU2 is DOUBLE PRECISION array, dimension (N-2)
The (n-2) elements of the second super-diagonal of U.

IPIV

IPIV is INTEGER array, dimension (N)
The pivot indices; for 1 <= i <= n, row i of the matrix was
interchanged with row IPIV(i).  IPIV(i) will always be either
i or i+1; IPIV(i) = i indicates a row interchange was not
required.

B

B is DOUBLE PRECISION array, dimension (LDB,NRHS)
On entry, the matrix of right hand side vectors B.
On exit, B is overwritten by 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 = -i, the i-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 138 of file dgttrs.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

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

Sat Nov 16 2013 Version 3.4.2 LAPACK