dposv.f man page
dposv.f subroutine dposv (UPLO, N, NRHS, A, LDA, B, LDB, INFO) DPOSV computes the solution to system of linear equations A * X = B for PO matrices Purpose: UPLO N NRHS A LDA B LDB INFO Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. December 2016 Definition at line 132 of file dposv.f. Generated automatically by Doxygen for LAPACK from the source code. The man page dposv(3) is an alias of dposv.f(3).Synopsis
Functions/Subroutines
DPOSV computes the solution to system of linear equations A * X = B for PO matricesFunction/Subroutine Documentation
subroutine dposv (character UPLO, integer N, integer NRHS, double precision, dimension( lda, * ) A, integer LDA, double precision, dimension( ldb, * ) B, integer LDB, integer INFO)
DPOSV computes the solution to a real system of linear equations
A * X = B,
where A is an N-by-N symmetric positive definite matrix and X and B
are N-by-NRHS matrices.
The Cholesky decomposition is used to factor A as
A = U**T* U, if UPLO = 'U', or
A = L * L**T, if UPLO = 'L',
where U is an upper triangular matrix and L is a lower triangular
matrix. The factored form of A is then used to solve the system of
equations A * X = B.
UPLO is CHARACTER*1
= 'U': Upper triangle of A is stored;
= 'L': Lower triangle of A is stored.
N is INTEGER
The number of linear equations, i.e., the order of the
matrix A. N >= 0.
NRHS is INTEGER
The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.
A is DOUBLE PRECISION array, dimension (LDA,N)
On entry, the symmetric matrix A. If UPLO = 'U', the leading
N-by-N upper triangular part of A contains the upper
triangular part of the matrix A, and the strictly lower
triangular part of A is not referenced. If UPLO = 'L', the
leading N-by-N lower triangular part of A contains the lower
triangular part of the matrix A, and the strictly upper
triangular part of A is not referenced.
On exit, if INFO = 0, the factor U or L from the Cholesky
factorization A = U**T*U or A = L*L**T.
LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,N).
B is DOUBLE PRECISION array, dimension (LDB,NRHS)
On entry, the N-by-NRHS right hand side matrix B.
On exit, if INFO = 0, the N-by-NRHS solution matrix X.
LDB is INTEGER
The leading dimension of the array B. LDB >= max(1,N).
INFO is 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 of A is not
positive definite, so the factorization could not be
completed, and the solution has not been computed.
Author
Referenced By