/**
Purpose
-------
DPOTRI computes the inverse of a real symmetric positive definite
matrix A using the Cholesky factorization A = U**T*U or A = L*L**T
computed by DPOTRF.
Arguments
---------
@param[in]
uplo magma_uplo_t
- = MagmaUpper: Upper triangle of A is stored;
- = MagmaLower: Lower triangle of A is stored.
@param[in]
n INTEGER
The order of the matrix A. N >= 0.
@param[in,out]
A DOUBLE_PRECISION array, dimension (LDA,N)
On entry, the triangular factor U or L from the Cholesky
factorization A = U**T*U or A = L*L**T, as computed by
DPOTRF.
On exit, the upper or lower triangle of the (symmetric)
inverse of A, overwriting the input factor U or L.
@param[in]
lda INTEGER
The leading dimension of the array A. LDA >= max(1,N).
@param[out]
info INTEGER
- = 0: successful exit
- < 0: if INFO = -i, the i-th argument had an illegal value
- > 0: if INFO = i, the (i,i) element of the factor U or L is
zero, and the inverse could not be computed.
@ingroup magma_dposv_comp
********************************************************************/
extern "C" magma_int_t
magma_dpotri(magma_uplo_t uplo, magma_int_t n,
double *A, magma_int_t lda, magma_int_t *info)
{
/* Local variables */
*info = 0;
if ((uplo != MagmaUpper) && (uplo != MagmaLower))
*info = -1;
else if (n < 0)
*info = -2;
else if (lda < max(1,n))
*info = -4;
if (*info != 0) {
magma_xerbla( __func__, -(*info) );
return *info;
}
/* Quick return if possible */
if ( n == 0 )
return *info;
/* Invert the triangular Cholesky factor U or L */
magma_dtrtri( uplo, MagmaNonUnit, n, A, lda, info );
if ( *info == 0 ) {
/* Form inv(U) * inv(U)**T or inv(L)**T * inv(L) */
magma_dlauum( uplo, n, A, lda, info );
}
return *info;
} /* magma_dpotri */
void magmaf_dtrtri(
magma_uplo_t *uplo, magma_diag_t *diag, magma_int_t *n,
double *A, magma_int_t *lda,
magma_int_t *info )
{
magma_dtrtri(
*uplo, *diag, *n,
A, *lda,
info );
}