dpptrs.f3
Usage
Functions/Subroutines
subroutine dpptrs (uplo, n, nrhs, ap, b, ldb, info)
DPPTRS
Function/Subroutine Documentation
subroutine dpptrs (character uplo, integer n, integer nrhs, double precision, dimension( * ) ap, double precision, dimension( ldb, * ) b, integer ldb, integer info)
DPPTRS
Purpose:
!> !> DPPTRS solves a system of linear equations A*X = B with a symmetric !> positive definite matrix A in packed storage using the Cholesky !> factorization A = U**T*U or A = L*L**T computed by DPPTRF. !>
Parameters
UPLO
!> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !>
N
!> N is INTEGER !> The order of the 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. !>
AP
!> AP is DOUBLE PRECISION array, dimension (N*(N+1)/2) !> The triangular factor U or L from the Cholesky factorization !> A = U**T*U or A = L*L**T, packed columnwise in a linear !> array. The j-th column of U or L is stored in the array AP !> as follows: !> if UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j; !> if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n. !>
B
!> B is DOUBLE PRECISION array, dimension (LDB,NRHS) !> On entry, the right hand side matrix B. !> On exit, the solution matrix 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.
Definition at line 107 of file dpptrs.f.
Releases
4 releases since Debian 7 (Wheezy); the text changed 3 times.