dpptrs (l) - Linux Manuals
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
Command to display dpptrs manual in Linux: $ man l dpptrs
NAME
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
SYNOPSIS
- SUBROUTINE DPPTRS(
-
UPLO, N, NRHS, AP, B, LDB, INFO )
-
CHARACTER
UPLO
-
INTEGER
INFO, LDB, N, NRHS
-
DOUBLE
PRECISION AP( * ), B( LDB, * )
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.
ARGUMENTS
- UPLO (input) CHARACTER*1
-
= aqUaq: Upper triangle of A is stored;
= aqLaq: Lower triangle of A is stored.
- 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) 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 = aqUaq, AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j;
if UPLO = aqLaq, AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.
- B (input/output) DOUBLE PRECISION 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