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488 lines
16 KiB

/* ========================================================================== */
/* === klu_analyze ========================================================== */
/* ========================================================================== */
/* Order the matrix using BTF (or not), and then AMD, COLAMD, the natural
* ordering, or the user-provided-function on the blocks. Does not support
* using a given ordering (use klu_analyze_given for that case). */
#include "klu_internal.h"
/* ========================================================================== */
/* === analyze_worker ======================================================= */
/* ========================================================================== */
static Int analyze_worker /* returns KLU_OK or < 0 if error */
(
/* inputs, not modified */
Int n, /* A is n-by-n */
Int Ap [ ], /* size n+1, column pointers */
Int Ai [ ], /* size nz, row indices */
Int nblocks, /* # of blocks */
Int Pbtf [ ], /* BTF row permutation */
Int Qbtf [ ], /* BTF col permutation */
Int R [ ], /* size n+1, but only Rbtf [0..nblocks] is used */
Int ordering, /* what ordering to use (0, 1, or 3 for this routine) */
/* output only, not defined on input */
Int P [ ], /* size n */
Int Q [ ], /* size n */
double Lnz [ ], /* size n, but only Lnz [0..nblocks-1] is used */
/* workspace, not defined on input or output */
Int Pblk [ ], /* size maxblock */
Int Cp [ ], /* size maxblock+1 */
Int Ci [ ], /* size MAX (nz+1, Cilen) */
Int Cilen, /* nz+1, or COLAMD_recommend(nz,n,n) for COLAMD */
Int Pinv [ ], /* size maxblock */
/* input/output */
KLU_symbolic *Symbolic,
KLU_common *Common
)
{
double amd_Info [AMD_INFO], lnz, lnz1, flops, flops1 ;
Int k1, k2, nk, k, block, oldcol, pend, newcol, result, pc, p, newrow,
maxnz, nzoff, cstats [COLAMD_STATS], ok, err = KLU_INVALID ;
/* ---------------------------------------------------------------------- */
/* initializations */
/* ---------------------------------------------------------------------- */
/* compute the inverse of Pbtf */
#ifndef NDEBUG
for (k = 0 ; k < n ; k++)
{
P [k] = EMPTY ;
Q [k] = EMPTY ;
Pinv [k] = EMPTY ;
}
#endif
for (k = 0 ; k < n ; k++)
{
ASSERT (Pbtf [k] >= 0 && Pbtf [k] < n) ;
Pinv [Pbtf [k]] = k ;
}
#ifndef NDEBUG
for (k = 0 ; k < n ; k++) ASSERT (Pinv [k] != EMPTY) ;
#endif
nzoff = 0 ;
lnz = 0 ;
maxnz = 0 ;
flops = 0 ;
Symbolic->symmetry = EMPTY ; /* only computed by AMD */
/* ---------------------------------------------------------------------- */
/* order each block */
/* ---------------------------------------------------------------------- */
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 ;
PRINTF (("BLOCK %d, k1 %d k2-1 %d nk %d\n", block, k1, k2-1, nk)) ;
/* ------------------------------------------------------------------ */
/* construct the kth block, C */
/* ------------------------------------------------------------------ */
Lnz [block] = EMPTY ;
pc = 0 ;
for (k = k1 ; k < k2 ; k++)
{
newcol = k-k1 ;
Cp [newcol] = pc ;
oldcol = Qbtf [k] ;
pend = Ap [oldcol+1] ;
for (p = Ap [oldcol] ; p < pend ; p++)
{
newrow = Pinv [Ai [p]] ;
if (newrow < k1)
{
nzoff++ ;
}
else
{
/* (newrow,newcol) is an entry in the block */
ASSERT (newrow < k2) ;
newrow -= k1 ;
Ci [pc++] = newrow ;
}
}
}
Cp [nk] = pc ;
maxnz = MAX (maxnz, pc) ;
ASSERT (KLU_valid (nk, Cp, Ci, NULL)) ;
/* ------------------------------------------------------------------ */
/* order the block C */
/* ------------------------------------------------------------------ */
if (nk <= 3)
{
/* -------------------------------------------------------------- */
/* use natural ordering for tiny blocks (3-by-3 or less) */
/* -------------------------------------------------------------- */
for (k = 0 ; k < nk ; k++)
{
Pblk [k] = k ;
}
lnz1 = nk * (nk + 1) / 2 ;
flops1 = nk * (nk - 1) / 2 + (nk-1)*nk*(2*nk-1) / 6 ;
ok = TRUE ;
}
else if (ordering == 0)
{
/* -------------------------------------------------------------- */
/* order the block with AMD (C+C') */
/* -------------------------------------------------------------- */
result = AMD_order (nk, Cp, Ci, Pblk, NULL, amd_Info) ;
ok = (result >= AMD_OK) ;
if (result == AMD_OUT_OF_MEMORY)
{
err = KLU_OUT_OF_MEMORY ;
}
/* account for memory usage in AMD */
Common->mempeak = MAX (Common->mempeak,
Common->memusage + amd_Info [AMD_MEMORY]) ;
/* get the ordering statistics from AMD */
lnz1 = (Int) (amd_Info [AMD_LNZ]) + nk ;
flops1 = 2 * amd_Info [AMD_NMULTSUBS_LU] + amd_Info [AMD_NDIV] ;
if (pc == maxnz)
{
/* get the symmetry of the biggest block */
Symbolic->symmetry = amd_Info [AMD_SYMMETRY] ;
}
}
else if (ordering == 1)
{
/* -------------------------------------------------------------- */
/* order the block with COLAMD (C) */
/* -------------------------------------------------------------- */
/* order (and destroy) Ci, returning column permutation in Cp.
* COLAMD "cannot" fail since the matrix has already been checked,
* and Ci allocated. */
ok = COLAMD (nk, nk, Cilen, Ci, Cp, NULL, cstats) ;
lnz1 = EMPTY ;
flops1 = EMPTY ;
/* copy the permutation from Cp to Pblk */
for (k = 0 ; k < nk ; k++)
{
Pblk [k] = Cp [k] ;
}
}
else
{
/* -------------------------------------------------------------- */
/* pass the block to the user-provided ordering function */
/* -------------------------------------------------------------- */
lnz1 = (Common->user_order) (nk, Cp, Ci, Pblk, Common) ;
flops1 = EMPTY ;
ok = (lnz1 != 0) ;
}
if (!ok)
{
return (err) ; /* ordering method failed */
}
/* ------------------------------------------------------------------ */
/* keep track of nnz(L) and flops statistics */
/* ------------------------------------------------------------------ */
Lnz [block] = lnz1 ;
lnz = (lnz == EMPTY || lnz1 == EMPTY) ? EMPTY : (lnz + lnz1) ;
flops = (flops == EMPTY || flops1 == EMPTY) ? EMPTY : (flops + flops1) ;
/* ------------------------------------------------------------------ */
/* combine the preordering with the BTF ordering */
/* ------------------------------------------------------------------ */
PRINTF (("Pblk, 1-based:\n")) ;
for (k = 0 ; k < nk ; k++)
{
ASSERT (k + k1 < n) ;
ASSERT (Pblk [k] + k1 < n) ;
Q [k + k1] = Qbtf [Pblk [k] + k1] ;
}
for (k = 0 ; k < nk ; k++)
{
ASSERT (k + k1 < n) ;
ASSERT (Pblk [k] + k1 < n) ;
P [k + k1] = Pbtf [Pblk [k] + k1] ;
}
}
PRINTF (("nzoff %d Ap[n] %d\n", nzoff, Ap [n])) ;
ASSERT (nzoff >= 0 && nzoff <= Ap [n]) ;
/* return estimates of # of nonzeros in L including diagonal */
Symbolic->lnz = lnz ; /* EMPTY if COLAMD used */
Symbolic->unz = lnz ;
Symbolic->nzoff = nzoff ;
Symbolic->est_flops = flops ; /* EMPTY if COLAMD or user-ordering used */
return (KLU_OK) ;
}
/* ========================================================================== */
/* === order_and_analyze ==================================================== */
/* ========================================================================== */
/* Orders the matrix with or with BTF, then orders each block with AMD, COLAMD,
* or the user ordering function. Does not handle the natural or given
* ordering cases. */
static KLU_symbolic *order_and_analyze /* returns NULL if error, or a valid
KLU_symbolic object if successful */
(
/* inputs, not modified */
Int n, /* A is n-by-n */
Int Ap [ ], /* size n+1, column pointers */
Int Ai [ ], /* size nz, row indices */
/* --------------------- */
KLU_common *Common
)
{
double work ;
KLU_symbolic *Symbolic ;
double *Lnz ;
Int *Qbtf, *Cp, *Ci, *Pinv, *Pblk, *Pbtf, *P, *Q, *R ;
Int nblocks, nz, block, maxblock, k1, k2, nk, do_btf, ordering, k, Cilen,
*Work ;
/* ---------------------------------------------------------------------- */
/* allocate the Symbolic object, and check input matrix */
/* ---------------------------------------------------------------------- */
Symbolic = KLU_alloc_symbolic (n, Ap, Ai, Common) ;
if (Symbolic == NULL)
{
return (NULL) ;
}
P = Symbolic->P ;
Q = Symbolic->Q ;
R = Symbolic->R ;
Lnz = Symbolic->Lnz ;
nz = Symbolic->nz ;
ordering = Common->ordering ;
if (ordering == 1)
{
/* COLAMD */
Cilen = COLAMD_recommended (nz, n, n) ;
}
else if (ordering == 0 || (ordering == 3 && Common->user_order != NULL))
{
/* AMD or user ordering function */
Cilen = nz+1 ;
}
else
{
/* invalid ordering */
Common->status = KLU_INVALID ;
KLU_free_symbolic (&Symbolic, Common) ;
return (NULL) ;
}
/* AMD memory management routines */
amd_malloc = Common->malloc_memory ;
amd_free = Common->free_memory ;
amd_calloc = Common->calloc_memory ;
amd_realloc = Common->realloc_memory ;
/* ---------------------------------------------------------------------- */
/* allocate workspace for BTF permutation */
/* ---------------------------------------------------------------------- */
Pbtf = KLU_malloc (n, sizeof (Int), Common) ;
Qbtf = KLU_malloc (n, sizeof (Int), Common) ;
if (Common->status < KLU_OK)
{
KLU_free (Pbtf, n, sizeof (Int), Common) ;
KLU_free (Qbtf, n, sizeof (Int), Common) ;
KLU_free_symbolic (&Symbolic, Common) ;
return (NULL) ;
}
/* ---------------------------------------------------------------------- */
/* get the common parameters for BTF and ordering method */
/* ---------------------------------------------------------------------- */
do_btf = Common->btf ;
do_btf = (do_btf) ? TRUE : FALSE ;
Symbolic->ordering = ordering ;
Symbolic->do_btf = do_btf ;
Symbolic->structural_rank = EMPTY ;
/* ---------------------------------------------------------------------- */
/* find the block triangular form (if requested) */
/* ---------------------------------------------------------------------- */
Common->work = 0 ;
if (do_btf)
{
Work = KLU_malloc (5*n, sizeof (Int), Common) ;
if (Common->status < KLU_OK)
{
/* out of memory */
KLU_free (Pbtf, n, sizeof (Int), Common) ;
KLU_free (Qbtf, n, sizeof (Int), Common) ;
KLU_free_symbolic (&Symbolic, Common) ;
return (NULL) ;
}
nblocks = BTF_order (n, Ap, Ai, Common->maxwork, &work, Pbtf, Qbtf, R,
&(Symbolic->structural_rank), Work) ;
Common->structural_rank = Symbolic->structural_rank ;
Common->work += work ;
KLU_free (Work, 5*n, sizeof (Int), Common) ;
/* unflip Qbtf if the matrix does not have full structural rank */
if (Symbolic->structural_rank < n)
{
for (k = 0 ; k < n ; k++)
{
Qbtf [k] = BTF_UNFLIP (Qbtf [k]) ;
}
}
/* find the size of the largest block */
maxblock = 1 ;
for (block = 0 ; block < nblocks ; block++)
{
k1 = R [block] ;
k2 = R [block+1] ;
nk = k2 - k1 ;
PRINTF (("block %d size %d\n", block, nk)) ;
maxblock = MAX (maxblock, nk) ;
}
}
else
{
/* BTF not requested */
nblocks = 1 ;
maxblock = n ;
R [0] = 0 ;
R [1] = n ;
for (k = 0 ; k < n ; k++)
{
Pbtf [k] = k ;
Qbtf [k] = k ;
}
}
Symbolic->nblocks = nblocks ;
PRINTF (("maxblock size %d\n", maxblock)) ;
Symbolic->maxblock = maxblock ;
/* ---------------------------------------------------------------------- */
/* allocate more workspace, for analyze_worker */
/* ---------------------------------------------------------------------- */
Pblk = KLU_malloc (maxblock, sizeof (Int), Common) ;
Cp = KLU_malloc (maxblock + 1, sizeof (Int), Common) ;
Ci = KLU_malloc (MAX (Cilen, nz+1), sizeof (Int), Common) ;
Pinv = KLU_malloc (n, sizeof (Int), Common) ;
/* ---------------------------------------------------------------------- */
/* order each block of the BTF ordering, and a fill-reducing ordering */
/* ---------------------------------------------------------------------- */
if (Common->status == KLU_OK)
{
PRINTF (("calling analyze_worker\n")) ;
Common->status = analyze_worker (n, Ap, Ai, nblocks, Pbtf, Qbtf, R,
ordering, P, Q, Lnz, Pblk, Cp, Ci, Cilen, Pinv, Symbolic, Common) ;
PRINTF (("analyze_worker done\n")) ;
}
/* ---------------------------------------------------------------------- */
/* free all workspace */
/* ---------------------------------------------------------------------- */
KLU_free (Pblk, maxblock, sizeof (Int), Common) ;
KLU_free (Cp, maxblock+1, sizeof (Int), Common) ;
KLU_free (Ci, MAX (Cilen, nz+1), sizeof (Int), Common) ;
KLU_free (Pinv, n, sizeof (Int), Common) ;
KLU_free (Pbtf, n, sizeof (Int), Common) ;
KLU_free (Qbtf, n, sizeof (Int), Common) ;
/* ---------------------------------------------------------------------- */
/* return the symbolic object */
/* ---------------------------------------------------------------------- */
if (Common->status < KLU_OK)
{
KLU_free_symbolic (&Symbolic, Common) ;
}
return (Symbolic) ;
}
/* ========================================================================== */
/* === KLU_analyze ========================================================== */
/* ========================================================================== */
KLU_symbolic *KLU_analyze /* returns NULL if error, or a valid
KLU_symbolic object if successful */
(
/* inputs, not modified */
Int n, /* A is n-by-n */
Int Ap [ ], /* size n+1, column pointers */
Int Ai [ ], /* size nz, row indices */
/* -------------------- */
KLU_common *Common
)
{
/* ---------------------------------------------------------------------- */
/* get the control parameters for BTF and ordering method */
/* ---------------------------------------------------------------------- */
if (Common == NULL)
{
return (NULL) ;
}
Common->status = KLU_OK ;
Common->structural_rank = EMPTY ;
/* ---------------------------------------------------------------------- */
/* order and analyze */
/* ---------------------------------------------------------------------- */
if (Common->ordering == 2)
{
/* natural ordering */
return (KLU_analyze_given (n, Ap, Ai, NULL, NULL, Common)) ;
}
else
{
/* order with P and Q */
return (order_and_analyze (n, Ap, Ai, Common)) ;
}
}