Function

NumCosmoMathlapack_dsytrf

Declaration [src]

gint
ncm_lapack_dsytrf (
  gchar uplo,
  gint n,
  gdouble* a,
  gint lda,
  gint* ipiv,
  NcmLapackWS* ws
)

Description [src]

This function computes the factorization of a real symmetric matrix a, using the Bunch-Kaufman diagonal pivoting method.

Parameters

uplo

Type: gchar

‘U’ upper triangle of a is stored; ‘L’ lower triangle of a is stored.

n

Type: gint

The order of the matrix a, n >= 0.

a

Type: gdouble*

Array of doubles with dimension (n, lda).

The data is owned by the caller of the function.

lda

Type: gint

The leading dimension of the array a, lda >= max (1, n).

ipiv

Type: gint*

Information about decomposition swaps and blocks.

The data is owned by the caller of the function.

ws

Type: NcmLapackWS

A NcmLapackWS.

The data is owned by the caller of the function.

Return value

Type: gint

I = 0: successful exit

     < 0:  -i, the i-th argument had an illegal value

     > 0: the (i,i) element of the factor U
       or L is zero, and the inverse could not be computed.