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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "./LIB/heads.h"
#include "./LIB/protos.h"
/*-----------------------------------------------------------------------*/
void dscale(int , double*, double*, double*);
p4ptr Lvsol2(double *x, int nlev, p4ptr levmat, ilutptr ilusch) ;
int Uvsol2(double *x, int nlev, int n, p4ptr levmat,
ilutptr ilusch);
void SchLsol(ilutptr ilusch, double *y) ;
void SchUsol(ilutptr ilusch, double *y) ;
/*-----------------------------------------------------------------------*/
p4ptr Lvsol2(double *x, int nlev, p4ptr levmat, ilutptr ilusch)
{
/* Macro L-solve -- corresponds to left (L) part of arms
| preconditioning operation --
| on entry :
| x = right- hand side to be operated on by the preconditioner
| on return : x is overwritten
| x = output result of operation
|
| Note : in-place operation -- b and x can occupy the same space..
| --------------------------------------------------------------------*/
/*-------------------- local variables */
int nloc=levmat->n, first, lenB;
p4ptr last=levmat;
/*-------------------- take care of special cases : nlev==0 --> lusol */
if (nlev == 0) {
SchLsol(ilusch,x);
return (last);
}
first = 0;
/*-------------------- descend */
while (levmat) {
nloc=levmat->n;
lenB =levmat->nB;
/*-------------------- left scaling */
if (levmat->D1 != NULL)
dscale(nloc,levmat->D1, &x[first], &x[first]);
/*-------------------- RESTRICTION/ DESCENT OPERATION */
if (lenB)
descend (levmat, &x[first], &x[first]);
first += lenB;
last = levmat;
levmat = levmat->next;
/*---------------------------------------------------------------------
| next level
+--------------------------------------------------------------------*/
}
SchLsol(ilusch,&x[first]);
return last;
}
int Uvsol2(double *x, int nlev, int n, p4ptr levmat,
ilutptr ilusch)
{
/* Macro U-solve -- corresponds to left (L) part of arms
| preconditioning operation --
| on entry :
| b = right- hand side to be operated on by the preconditioner
| on return = x has been overwritten =
| x = output result of operation
|
| Note : in-place operation -- b and x can occupy the same space..
| --------------------------------------------------------------------*/
/*-------------------- local variables */
int nloc, lenB, first;
/*-------------------- work array */
/*-------------------- take care of special cases : nlev==0 --> lusol */
/*-------------------- case of zero levels */
if (nlev == 0) {
SchUsol(ilusch, x);
return(0);
}
/*-------------------- general case */
nloc=levmat->n;
lenB=levmat->nB;
first = n - nloc;
/*-------------------- last level */
first += lenB;
SchUsol(ilusch, &x[first]);
/*-------------------- other levels */
while (levmat) {
nloc = levmat->n;
first -= levmat->nB;
if (levmat->n)
ascend(levmat, &x[first],&x[first]);
/*-------------------- right scaling */
if (levmat->D2 != NULL)
dscale(nloc, levmat->D2, &x[first], &x[first]) ;
levmat = levmat->prev;
}
return 0;
/*-------------------- PROLONGATION/ ASCENT OPERATION */
}
int armsol2(double *x, arms Prec)
{ /* combined preconditioning operation -- combines the
| left and right actions.
|
| on entry :
| x = right- hand side to be operated on by the preconditioner
| on return : x is overwritten -
| x = output result of operation
|
| Note : in-place operation -- b and x can occupy the same space..
| --------------------------------------------------------------------*/
/*-------------------- local variables */
p4ptr levmat = Prec->levmat;
ilutptr ilusch = Prec->ilus;
int nlev = Prec->nlev;
int n = levmat->n;
p4ptr last;
if (nlev == 0) {
n = ilusch->n;
SchLsol(ilusch, x);
SchUsol(ilusch, x);
return 0;
}
last = Lvsol2(x, nlev, levmat, ilusch) ;
Uvsol2(x, nlev, n, last, ilusch) ;
return 0;
}
void SchLsol(ilutptr ilusch, double *y)
{
/*---------------------------------------------------------------------
| Forward solve for Schur complement part =
|----------------------------------------------------------------------
| on entry:
| ilusch = the LU matrix as provided from the ILU functions.
| y = the right-hand-side vector
|
| on return
| y = solution of LU x = y. [overwritten]
|---------------------------------------------------------------------*/
/*-------------------- local variables */
int n = ilusch->n, j, *perm = ilusch->rperm;
double *work = ilusch->wk;
/*-------------------- begin: right scaling */
if (ilusch->D1 != NULL)
dscale(n, ilusch->D1, y, y);
/*-------------------- ONE SIDED ROW PERMS */
if (perm != NULL) {
for (j=0; j<n; j++)
work[perm[j]] = y[j];
/*-------------------- L solve proper */
Lsol(ilusch->L, work, y);
} else
Lsol(ilusch->L, y, y);
/*---------------end of SchLsol---------------------------------------
----------------------------------------------------------------------*/
}
void SchUsol(ilutptr ilusch, double *y)
{
/*---------------------------------------------------------------------
| U-solve for Schur complement -
|----------------------------------------------------------------------
| on entry:
| ilusch = the LU matrix as provided from the ILU functions.
| y = the right-hand-side vector
|
| on return
| y = solution of U x = y. [overwritten on y]
|----------------------------------------------------------------------*/
int n = ilusch->n, j, *perm = ilusch->perm, *cperm;
double *work = ilusch->wk;
/* -------------------- begin by U-solving */
/*-------------------- CASE: column pivoting used (as in ILUTP) */
if (ilusch->perm2 != NULL) {
Usol(ilusch->U, y, y);
cperm = ilusch->perm2;
for (j=0; j<n; j++)
work[cperm[j]] = y[j];
}
else
/*-------------------- CASE: no column pivoting used */
Usol(ilusch->U, y, work);
/*-------------------- generic permutation */
if (perm != NULL) {
for (j=0; j<n; j++)
y[j] = work[perm[j]];
} else
memcpy(y, work,n*sizeof(double));
/*-------------------- case when diagonal scaling is done on columns */
if (ilusch->D2 !=NULL)
dscale(n, ilusch->D2, y, y);
}
/*---------------end of SchUsol---------------------------------------
----------------------------------------------------------------------*/
|
