subroutine cptts2 (IUPLO, N, NRHS, D, E, B, LDB)
CPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf.
CPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf.
Purpose:
CPTTS2 solves a tridiagonal system of the form
A * X = B
using the factorization A = U**H*D*U or A = L*D*L**H computed by CPTTRF.
D is a diagonal matrix specified in the vector D, U (or L) is a unit
bidiagonal matrix whose superdiagonal (subdiagonal) is specified in
the vector E, and X and B are N by NRHS matrices.
Parameters:
IUPLO is INTEGER
Specifies the form of the factorization and whether the
vector E is the superdiagonal of the upper bidiagonal factor
U or the subdiagonal of the lower bidiagonal factor L.
= 1: A = U**H *D*U, E is the superdiagonal of U
= 0: A = L*D*L**H, E is the subdiagonal of L
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 REAL array, dimension (N)
The n diagonal elements of the diagonal matrix D from the
factorization A = U**H *D*U or A = L*D*L**H.
E
E is COMPLEX array, dimension (N-1)
If IUPLO = 1, the (n-1) superdiagonal elements of the unit
bidiagonal factor U from the factorization A = U**H*D*U.
If IUPLO = 0, the (n-1) subdiagonal elements of the unit
bidiagonal factor L from the factorization A = L*D*L**H.
B
B is COMPLEX 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).
Author:
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
Definition at line 115 of file cptts2.f.
Generated automatically by Doxygen for LAPACK from the source code.