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/* ========================================================================== */
/* === UMFPACK_scale ======================================================== */
/* ========================================================================== */
/* -------------------------------------------------------------------------- */
/* UMFPACK Copyright (c) Timothy A. Davis, CISE, */
/* Univ. of Florida. All Rights Reserved. See ../Doc/License for License. */
/* web: http://www.cise.ufl.edu/research/sparse/umfpack */
/* -------------------------------------------------------------------------- */
/*
User-callable. Applies the scale factors computed during numerical
factorization to a vector. See umfpack_scale.h for more details.
The LU factorization is L*U = P*R*A*Q, where P and Q are permutation
matrices, and R is diagonal. This routine computes X = R * B using the
matrix R stored in the Numeric object.
Returns FALSE if any argument is invalid, TRUE otherwise.
If R not present in the Numeric object, then R = I and no floating-point
work is done. B is simply copied into X.
*/
#include "umf_internal.h"
#include "umf_valid_numeric.h"
GLOBAL Int UMFPACK_scale
(
double Xx [ ],
#ifdef COMPLEX
double Xz [ ],
#endif
const double Bx [ ],
#ifdef COMPLEX
const double Bz [ ],
#endif
void *NumericHandle
)
{
/* ---------------------------------------------------------------------- */
/* local variables */
/* ---------------------------------------------------------------------- */
NumericType *Numeric ;
Int n, i ;
double *Rs ;
#ifdef COMPLEX
Int split = SPLIT (Xz) && SPLIT (Bz) ;
#endif
Numeric = (NumericType *) NumericHandle ;
if (!UMF_valid_numeric (Numeric))
{
return (UMFPACK_ERROR_invalid_Numeric_object) ;
}
n = Numeric->n_row ;
Rs = Numeric->Rs ;
if (!Xx || !Bx)
{
return (UMFPACK_ERROR_argument_missing) ;
}
/* ---------------------------------------------------------------------- */
/* X = R*B or R\B */
/* ---------------------------------------------------------------------- */
if (Rs != (double *) NULL)
{
#ifndef NRECIPROCAL
if (Numeric->do_recip)
{
/* multiply by the scale factors */
#ifdef COMPLEX
if (split)
{
for (i = 0 ; i < n ; i++)
{
Xx [i] = Bx [i] * Rs [i] ;
Xz [i] = Bz [i] * Rs [i] ;
}
}
else
{
for (i = 0 ; i < n ; i++)
{
Xx [2*i ] = Bx [2*i ] * Rs [i] ;
Xx [2*i+1] = Bx [2*i+1] * Rs [i] ;
}
}
#else
for (i = 0 ; i < n ; i++)
{
Xx [i] = Bx [i] * Rs [i] ;
}
#endif
}
else
#endif
{
/* divide by the scale factors */
#ifdef COMPLEX
if (split)
{
for (i = 0 ; i < n ; i++)
{
Xx [i] = Bx [i] / Rs [i] ;
Xz [i] = Bz [i] / Rs [i] ;
}
}
else
{
for (i = 0 ; i < n ; i++)
{
Xx [2*i ] = Bx [2*i ] / Rs [i] ;
Xx [2*i+1] = Bx [2*i+1] / Rs [i] ;
}
}
#else
for (i = 0 ; i < n ; i++)
{
Xx [i] = Bx [i] / Rs [i] ;
}
#endif
}
}
else
{
/* no scale factors, just copy B into X */
#ifdef COMPLEX
if (split)
{
for (i = 0 ; i < n ; i++)
{
Xx [i] = Bx [i] ;
Xz [i] = Bz [i] ;
}
}
else
{
for (i = 0 ; i < n ; i++)
{
Xx [2*i ] = Bx [2*i ] ;
Xx [2*i+1] = Bx [2*i+1] ;
}
}
#else
for (i = 0 ; i < n ; i++)
{
Xx [i] = Bx [i] ;
}
#endif
}
return (UMFPACK_OK) ;
}
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