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/*
Copyright (C) 2014, The University of Texas at Austin
This file is part of libflame and is available under the 3-Clause
BSD license, which can be found in the LICENSE file at the top-level
directory, or at http://opensource.org/licenses/BSD-3-Clause
*/
#include <math.h>
#include "FLAME.h"
#include "Chol_prototypes.h"
#define AA(i,j) buff_A[ (j)*ldim_A + (i) ]
FLA_Error REF_Chol( FLA_Obj A )
{
int n, i, j, k, ldim_A;
double *buff_A;
n = FLA_Obj_length( A );
ldim_A = FLA_Obj_col_stride( A );
buff_A = (double *) FLA_Obj_buffer_at_view( A );
for ( j=0; j<n; j++ ){
AA( j,j ) = sqrt( AA( j,j ) );
/* a21 = a21 / alpha11 */
for ( i=j+1; i<n; i++ )
AA( i,j ) = AA( i,j ) / AA( j,j );
/* A22 = A22 - a21 * a21' (lower triangular part only) */
for ( k=j+1; k<n; k++ )
for ( i=k; i<n; i++ )
AA( i,k ) = AA( i,k ) - AA( i,j ) * AA( j,k );
}
}
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