Int KLU_refactor /* returns TRUE if successful, FALSE otherwise */
(
/* inputs, not modified */
Int Ap [ ], /* size n+1, column pointers */
Int Ai [ ], /* size nz, row indices */
double Ax [ ],
KLU_symbolic<Entry, Int> *Symbolic,
/* input/output */
KLU_numeric<Entry, Int> *Numeric,
KLU_common<Entry, Int> *Common
)
{
Entry ukk, ujk, s ;
Entry *Offx, *Lx, *Ux, *X, *Az, *Udiag ;
double *Rs ;
Int *P, *Q, *R, *Pnum, *Offp, *Offi, *Ui, *Li, *Pinv, *Lip, *Uip, *Llen,
*Ulen ;
Unit **LUbx ;
Unit *LU ;
Int k1, k2, nk, k, block, oldcol, pend, oldrow, n, p, newrow, scale,
nblocks, poff, i, j, up, ulen, llen, maxblock, nzoff ;
/* ---------------------------------------------------------------------- */
/* check inputs */
/* ---------------------------------------------------------------------- */
if (Common == NULL)
{
return (FALSE) ;
}
Common->status = KLU_OK ;
if (Numeric == NULL)
{
/* invalid Numeric object */
Common->status = KLU_INVALID ;
return (FALSE) ;
}
Common->numerical_rank = EMPTY ;
Common->singular_col = EMPTY ;
Az = (Entry *) Ax ;
/* ---------------------------------------------------------------------- */
/* get the contents of the Symbolic object */
/* ---------------------------------------------------------------------- */
n = Symbolic->n ;
P = Symbolic->P ;
Q = Symbolic->Q ;
R = Symbolic->R ;
nblocks = Symbolic->nblocks ;
maxblock = Symbolic->maxblock ;
/* ---------------------------------------------------------------------- */
/* get the contents of the Numeric object */
/* ---------------------------------------------------------------------- */
Pnum = Numeric->Pnum ;
Offp = Numeric->Offp ;
Offi = Numeric->Offi ;
Offx = (Entry *) Numeric->Offx ;
LUbx = (Unit **) Numeric->LUbx ;
scale = Common->scale ;
if (scale > 0)
{
/* factorization was not scaled, but refactorization is scaled */
if (Numeric->Rs == NULL)
{
Numeric->Rs = (double *)KLU_malloc (n, sizeof (double), Common) ;
if (Common->status < KLU_OK)
{
Common->status = KLU_OUT_OF_MEMORY ;
return (FALSE) ;
}
}
}
else
{
/* no scaling for refactorization; ensure Numeric->Rs is freed. This
* does nothing if Numeric->Rs is already NULL. */
Numeric->Rs = (double *) KLU_free (Numeric->Rs, n, sizeof (double), Common) ;
}
Rs = Numeric->Rs ;
Pinv = Numeric->Pinv ;
X = (Entry *) Numeric->Xwork ;
Common->nrealloc = 0 ;
Udiag = (Entry *) Numeric->Udiag ;
nzoff = Symbolic->nzoff ;
/* ---------------------------------------------------------------------- */
/* check the input matrix compute the row scale factors, Rs */
/* ---------------------------------------------------------------------- */
/* do no scale, or check the input matrix, if scale < 0 */
if (scale >= 0)
{
/* check for out-of-range indices, but do not check for duplicates */
if (!KLU_scale (scale, n, Ap, Ai, Ax, Rs, NULL, Common))
{
return (FALSE) ;
}
}
/* ---------------------------------------------------------------------- */
/* clear workspace X */
/* ---------------------------------------------------------------------- */
for (k = 0 ; k < maxblock ; k++)
{
/* X [k] = 0 */
CLEAR (X [k]) ;
}
poff = 0 ;
/* ---------------------------------------------------------------------- */
/* factor each block */
/* ---------------------------------------------------------------------- */
if (scale <= 0)
{
/* ------------------------------------------------------------------ */
/* no scaling */
/* ------------------------------------------------------------------ */
for (block = 0 ; block < nblocks ; block++)
{
/* -------------------------------------------------------------- */
/* the block is from rows/columns k1 to k2-1 */
/* -------------------------------------------------------------- */
k1 = R [block] ;
k2 = R [block+1] ;
nk = k2 - k1 ;
if (nk == 1)
{
/* ---------------------------------------------------------- */
/* singleton case */
/* ---------------------------------------------------------- */
oldcol = Q [k1] ;
pend = Ap [oldcol+1] ;
CLEAR (s) ;
for (p = Ap [oldcol] ; p < pend ; p++)
{
newrow = Pinv [Ai [p]] - k1 ;
if (newrow < 0 && poff < nzoff)
{
/* entry in off-diagonal block */
Offx [poff] = Az [p] ;
poff++ ;
}
else
{
/* singleton */
s = Az [p] ;
}
}
Udiag [k1] = s ;
}
else
{
/* ---------------------------------------------------------- */
/* construct and factor the kth block */
/* ---------------------------------------------------------- */
Lip = Numeric->Lip + k1 ;
Llen = Numeric->Llen + k1 ;
Uip = Numeric->Uip + k1 ;
Ulen = Numeric->Ulen + k1 ;
LU = LUbx [block] ;
for (k = 0 ; k < nk ; k++)
{
/* ------------------------------------------------------ */
/* scatter kth column of the block into workspace X */
/* ------------------------------------------------------ */
oldcol = Q [k+k1] ;
pend = Ap [oldcol+1] ;
for (p = Ap [oldcol] ; p < pend ; p++)
{
newrow = Pinv [Ai [p]] - k1 ;
if (newrow < 0 && poff < nzoff)
{
/* entry in off-diagonal block */
Offx [poff] = Az [p] ;
poff++ ;
}
else
{
/* (newrow,k) is an entry in the block */
X [newrow] = Az [p] ;
}
}
/* ------------------------------------------------------ */
/* compute kth column of U, and update kth column of A */
/* ------------------------------------------------------ */
GET_POINTER (LU, Uip, Ulen, Ui, Ux, k, ulen) ;
for (up = 0 ; up < ulen ; up++)
{
j = Ui [up] ;
ujk = X [j] ;
/* X [j] = 0 */
CLEAR (X [j]) ;
Ux [up] = ujk ;
GET_POINTER (LU, Lip, Llen, Li, Lx, j, llen) ;
for (p = 0 ; p < llen ; p++)
{
/* X [Li [p]] -= Lx [p] * ujk */
MULT_SUB (X [Li [p]], Lx [p], ujk) ;
}
}
/* get the diagonal entry of U */
ukk = X [k] ;
/* X [k] = 0 */
CLEAR (X [k]) ;
/* singular case */
if (IS_ZERO (ukk))
{
/* matrix is numerically singular */
Common->status = KLU_SINGULAR ;
if (Common->numerical_rank == EMPTY)
{
Common->numerical_rank = k+k1 ;
Common->singular_col = Q [k+k1] ;
}
if (Common->halt_if_singular)
{
/* do not continue the factorization */
return (FALSE) ;
}
}
Udiag [k+k1] = ukk ;
/* gather and divide by pivot to get kth column of L */
GET_POINTER (LU, Lip, Llen, Li, Lx, k, llen) ;
for (p = 0 ; p < llen ; p++)
{
i = Li [p] ;
DIV (Lx [p], X [i], ukk) ;
CLEAR (X [i]) ;
}
}
}
}
}
else
{
/* ------------------------------------------------------------------ */
/* scaling */
/* ------------------------------------------------------------------ */
for (block = 0 ; block < nblocks ; block++)
{
/* -------------------------------------------------------------- */
/* the block is from rows/columns k1 to k2-1 */
/* -------------------------------------------------------------- */
k1 = R [block] ;
k2 = R [block+1] ;
nk = k2 - k1 ;
if (nk == 1)
{
/* ---------------------------------------------------------- */
/* singleton case */
/* ---------------------------------------------------------- */
oldcol = Q [k1] ;
pend = Ap [oldcol+1] ;
CLEAR (s) ;
for (p = Ap [oldcol] ; p < pend ; p++)
{
oldrow = Ai [p] ;
newrow = Pinv [oldrow] - k1 ;
if (newrow < 0 && poff < nzoff)
{
/* entry in off-diagonal block */
/* Offx [poff] = Az [p] / Rs [oldrow] */
SCALE_DIV_ASSIGN (Offx [poff], Az [p], Rs [oldrow]) ;
poff++ ;
}
else
{
/* singleton */
/* s = Az [p] / Rs [oldrow] */
SCALE_DIV_ASSIGN (s, Az [p], Rs [oldrow]) ;
}
}
Udiag [k1] = s ;
}
else
{
/* ---------------------------------------------------------- */
/* construct and factor the kth block */
/* ---------------------------------------------------------- */
Lip = Numeric->Lip + k1 ;
Llen = Numeric->Llen + k1 ;
Uip = Numeric->Uip + k1 ;
Ulen = Numeric->Ulen + k1 ;
LU = LUbx [block] ;
for (k = 0 ; k < nk ; k++)
{
/* ------------------------------------------------------ */
/* scatter kth column of the block into workspace X */
/* ------------------------------------------------------ */
oldcol = Q [k+k1] ;
pend = Ap [oldcol+1] ;
for (p = Ap [oldcol] ; p < pend ; p++)
{
oldrow = Ai [p] ;
newrow = Pinv [oldrow] - k1 ;
if (newrow < 0 && poff < nzoff)
{
/* entry in off-diagonal part */
/* Offx [poff] = Az [p] / Rs [oldrow] */
SCALE_DIV_ASSIGN (Offx [poff], Az [p], Rs [oldrow]);
poff++ ;
}
else
{
/* (newrow,k) is an entry in the block */
/* X [newrow] = Az [p] / Rs [oldrow] */
SCALE_DIV_ASSIGN (X [newrow], Az [p], Rs [oldrow]) ;
}
}
/* ------------------------------------------------------ */
/* compute kth column of U, and update kth column of A */
/* ------------------------------------------------------ */
GET_POINTER (LU, Uip, Ulen, Ui, Ux, k, ulen) ;
for (up = 0 ; up < ulen ; up++)
{
j = Ui [up] ;
ujk = X [j] ;
/* X [j] = 0 */
CLEAR (X [j]) ;
Ux [up] = ujk ;
GET_POINTER (LU, Lip, Llen, Li, Lx, j, llen) ;
for (p = 0 ; p < llen ; p++)
{
/* X [Li [p]] -= Lx [p] * ujk */
MULT_SUB (X [Li [p]], Lx [p], ujk) ;
}
}
/* get the diagonal entry of U */
ukk = X [k] ;
/* X [k] = 0 */
CLEAR (X [k]) ;
/* singular case */
if (IS_ZERO (ukk))
{
/* matrix is numerically singular */
Common->status = KLU_SINGULAR ;
if (Common->numerical_rank == EMPTY)
{
Common->numerical_rank = k+k1 ;
Common->singular_col = Q [k+k1] ;
}
if (Common->halt_if_singular)
{
/* do not continue the factorization */
return (FALSE) ;
}
}
Udiag [k+k1] = ukk ;
/* gather and divide by pivot to get kth column of L */
GET_POINTER (LU, Lip, Llen, Li, Lx, k, llen) ;
for (p = 0 ; p < llen ; p++)
{
i = Li [p] ;
DIV (Lx [p], X [i], ukk) ;
CLEAR (X [i]) ;
}
}
}
}
}
/* ---------------------------------------------------------------------- */
/* permute scale factors Rs according to pivotal row order */
/* ---------------------------------------------------------------------- */
if (scale > 0)
{
for (k = 0 ; k < n ; k++)
{
/* TODO : Check. REAL(X[k]) Can be just X[k] */
/* REAL (X [k]) = Rs [Pnum [k]] ; */
X [k] = Rs [Pnum [k]] ;
}
for (k = 0 ; k < n ; k++)
{
Rs [k] = REAL (X [k]) ;
}
}
#ifndef NDEBUGKLU2
ASSERT (Offp [n] == poff) ;
ASSERT (Symbolic->nzoff == poff) ;
PRINTF (("\n------------------- Off diagonal entries, new:\n")) ;
ASSERT (KLU_valid (n, Offp, Offi, Offx)) ;
if (Common->status == KLU_OK)
{
PRINTF (("\n ########### KLU_BTF_REFACTOR done, nblocks %d\n",nblocks));
for (block = 0 ; block < nblocks ; block++)
{
k1 = R [block] ;
k2 = R [block+1] ;
nk = k2 - k1 ;
PRINTF ((
"\n================KLU_refactor output: k1 %d k2 %d nk %d\n",
k1, k2, nk)) ;
if (nk == 1)
{
PRINTF (("singleton ")) ;
PRINT_ENTRY (Udiag [k1]) ;
}
else
{
Lip = Numeric->Lip + k1 ;
Llen = Numeric->Llen + k1 ;
LU = (Unit *) Numeric->LUbx [block] ;
PRINTF (("\n---- L block %d\n", block)) ;
ASSERT (KLU_valid_LU (nk, TRUE, Lip, Llen, LU)) ;
Uip = Numeric->Uip + k1 ;
Ulen = Numeric->Ulen + k1 ;
PRINTF (("\n---- U block %d\n", block)) ;
ASSERT (KLU_valid_LU (nk, FALSE, Uip, Ulen, LU)) ;
}
}
}
#endif
return (TRUE) ;
}
static void sort (Int n, Int *Xip, Int *Xlen, Unit *LU, Int *Tp, Int *Tj,
Entry *Tx, Int *W)
{
Int *Xi ;
Entry *Xx ;
Int p, i, j, len, nz, tp, xlen, pend ;
ASSERT (KLU_valid_LU (n, FALSE, Xip, Xlen, LU)) ;
/* count the number of entries in each row of L or U */
for (i = 0 ; i < n ; i++)
{
W [i] = 0 ;
}
for (j = 0 ; j < n ; j++)
{
GET_POINTER (LU, Xip, Xlen, Xi, Xx, j, len) ;
for (p = 0 ; p < len ; p++)
{
W [Xi [p]]++ ;
}
}
/* construct the row pointers for T */
nz = 0 ;
for (i = 0 ; i < n ; i++)
{
Tp [i] = nz ;
nz += W [i] ;
}
Tp [n] = nz ;
for (i = 0 ; i < n ; i++)
{
W [i] = Tp [i] ;
}
/* transpose the matrix into Tp, Ti, Tx */
for (j = 0 ; j < n ; j++)
{
GET_POINTER (LU, Xip, Xlen, Xi, Xx, j, len) ;
for (p = 0 ; p < len ; p++)
{
tp = W [Xi [p]]++ ;
Tj [tp] = j ;
Tx [tp] = Xx [p] ;
}
}
/* transpose the matrix back into Xip, Xlen, Xi, Xx */
for (j = 0 ; j < n ; j++)
{
W [j] = 0 ;
}
for (i = 0 ; i < n ; i++)
{
pend = Tp [i+1] ;
for (p = Tp [i] ; p < pend ; p++)
{
j = Tj [p] ;
GET_POINTER (LU, Xip, Xlen, Xi, Xx, j, len) ;
xlen = W [j]++ ;
Xi [xlen] = i ;
Xx [xlen] = Tx [p] ;
}
}
ASSERT (KLU_valid_LU (n, FALSE, Xip, Xlen, LU)) ;
}
