cgtts2.f (3) Linux Manual Page
cgtts2.f –
Synopsis
Functions/Subroutines
subroutine cgtts2 (ITRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB)CGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf.
Function/Subroutine Documentation
subroutine cgtts2 (integerITRANS, integerN, integerNRHS, complex, dimension( * )DL, complex, dimension( * )D, complex, dimension( * )DU, complex, dimension( * )DU2, integer, dimension( * )IPIV, complex, dimension( ldb, * )B, integerLDB)
CGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf. Purpose:
CGTTS2 solves one of the systems of equations
A * X = B, A**T * X = B, or A**H * X = B,
with a tridiagonal matrix A using the LU factorization computed
by CGTTRF.
Parameters:
- ITRANS
ITRANS is INTEGER
N
Specifies the form of the system of equations.
= 0: A * X = B (No transpose)
= 1: A**T * X = B (Transpose)
= 2: A**H * X = B (Conjugate transpose)N is INTEGER
NRHS
The order of the matrix A.NRHS is INTEGER
DL
The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.DL is COMPLEX array, dimension (N-1)
D
The (n-1) multipliers that define the matrix L from the
LU factorization of A.D is COMPLEX array, dimension (N)
DU
The n diagonal elements of the upper triangular matrix U from
the LU factorization of A.DU is COMPLEX array, dimension (N-1)
DU2
The (n-1) elements of the first super-diagonal of U.DU2 is COMPLEX array, dimension (N-2)
IPIV
The (n-2) elements of the second super-diagonal of U.IPIV is INTEGER array, dimension (N)
B
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 is COMPLEX array, dimension (LDB,NRHS)
LDB
On entry, the matrix of right hand side vectors B.
On exit, B is overwritten by the solution vectors X.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.
Date:
- September 2012
Definition at line 129 of file cgtts2.f.
