dgttrs.f(3) LAPACK dgttrs.f(3)
**NAME**
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.
**Version 3.4.2** Tue Sep 25 2012 dgttrs.f(3)