NAME

CHPTRS - solve a system of linear equations A∗X = B with a complex Hermitian matrix A stored in packed format using the factorization A = U∗D∗U∗∗H or A = L∗D∗L∗∗H computed by CHPTRF

SYNOPSIS

SUBROUTINE CHPTRS(
UPLO, N, NRHS, AP, IPIV, B, LDB, INFO )

CHARACTER UPLO

INTEGER INFO, LDB, N, NRHS

INTEGER IPIV( ∗ )

COMPLEX AP( ∗ ), B( LDB, ∗ )

PURPOSE

CHPTRS solves a system of linear equations A∗X = B with a complex Hermitian matrix A stored in packed format using the factorization A = U∗D∗U∗∗H or A = L∗D∗L∗∗H computed by CHPTRF. 
 

ARGUMENTS

UPLO    (input) CHARACTER∗1
Specifies whether the details of the factorization are stored as an upper or lower triangular matrix. = ’U’:  Upper triangular, form is A = U∗D∗U∗∗H;
= ’L’:  Lower triangular, form is A = L∗D∗L∗∗H.

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.

AP      (input) COMPLEX array, dimension (N∗(N+1)/2)
The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by CHPTRF, stored as a packed triangular matrix.

IPIV    (input) INTEGER array, dimension (N)
Details of the interchanges and the block structure of D as determined by CHPTRF.

B       (input/output) COMPLEX array, dimension (LDB,NRHS)
On entry, the right hand side matrix B. On exit, the 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

  —  LAPACK version 2.0  —  08 October 1994