ZPTSV(3)
computes the solution to a complex system of linear equations A*X = B, where A is an N-by-N Hermitian positive definite tridiagonal matrix, and X and B are N-by-NRHS matrices
SYNOPSIS
- SUBROUTINE ZPTSV(
-
N, NRHS, D, E, B, LDB, INFO )
-
INTEGER
INFO, LDB, N, NRHS
-
DOUBLE
PRECISION D( * )
-
COMPLEX*16
B( LDB, * ), E( * )
PURPOSE
ZPTSV computes the solution to a complex system of linear equations
A*X = B, where A is an N-by-N Hermitian positive definite tridiagonal
matrix, and X and B are N-by-NRHS matrices.
A is factored as A = L*D*L**H, and the factored form of A is then
used to solve the system of equations.
ARGUMENTS
- N (input) INTEGER
-
The order of the matrix A. N >= 0.
- NRHS (input) INTEGER
-
The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.
- D (input/output) DOUBLE PRECISION 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**H.
- E (input/output) COMPLEX*16 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**H factorization of
A. E can also be regarded as the superdiagonal of the unit
bidiagonal factor U from the U**H*D*U factorization of A.
- B (input/output) COMPLEX*16 array, dimension (LDB,N)
-
On entry, the N-by-NRHS right hand side matrix B.
On exit, if INFO = 0, the N-by-NRHS solution matrix X.
- LDB (input) INTEGER
-
The leading dimension of the array B. LDB >= max(1,N).
- INFO (output) 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.