hypre/parcsr_linear_solvers/gmres.c

597 lines
16 KiB
C

/*BHEADER**********************************************************************
* (c) 1998 The Regents of the University of California
*
* See the file COPYRIGHT_and_DISCLAIMER for a complete copyright
* notice, contact person, and disclaimer.
*
* $Revision$
*********************************************************************EHEADER*/
/******************************************************************************
*
* GMRES gmres
*
*****************************************************************************/
#include "headers.h"
/*--------------------------------------------------------------------------
* hypre_GMRESData
*--------------------------------------------------------------------------*/
typedef struct
{
int k_dim;
int min_iter;
int max_iter;
int stop_crit;
double tol;
double rel_residual_norm;
void *A;
void *r;
void *w;
void **p;
void *matvec_data;
int (*precond)();
int (*precond_setup)();
void *precond_data;
/* log info (always logged) */
int num_iterations;
/* additional log info (logged when `logging' > 0) */
int logging;
double *norms;
char *log_file_name;
} hypre_GMRESData;
/*--------------------------------------------------------------------------
* hypre_GMRESCreate
*--------------------------------------------------------------------------*/
void *
hypre_GMRESCreate( )
{
hypre_GMRESData *gmres_data;
gmres_data = hypre_CTAlloc(hypre_GMRESData, 1);
/* set defaults */
(gmres_data -> k_dim) = 5;
(gmres_data -> tol) = 1.0e-06;
(gmres_data -> min_iter) = 0;
(gmres_data -> max_iter) = 1000;
(gmres_data -> stop_crit) = 0; /* rel. residual norm */
(gmres_data -> precond) = hypre_KrylovIdentity;
(gmres_data -> precond_setup) = hypre_KrylovIdentitySetup;
(gmres_data -> precond_data) = NULL;
(gmres_data -> logging) = 0;
(gmres_data -> p) = NULL;
(gmres_data -> r) = NULL;
(gmres_data -> w) = NULL;
(gmres_data -> matvec_data) = NULL;
(gmres_data -> norms) = NULL;
(gmres_data -> log_file_name) = NULL;
return (void *) gmres_data;
}
/*--------------------------------------------------------------------------
* hypre_GMRESDestroy
*--------------------------------------------------------------------------*/
int
hypre_GMRESDestroy( void *gmres_vdata )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int i, ierr = 0;
if (gmres_data)
{
if ((gmres_data -> logging) > 0)
{
hypre_TFree(gmres_data -> norms);
}
hypre_KrylovMatvecDestroy(gmres_data -> matvec_data);
hypre_KrylovDestroyVector(gmres_data -> r);
hypre_KrylovDestroyVector(gmres_data -> w);
for (i = 0; i < (gmres_data -> k_dim+1); i++)
{
hypre_KrylovDestroyVector( (gmres_data -> p) [i]);
}
hypre_TFree(gmres_data -> p);
hypre_TFree(gmres_data);
}
return(ierr);
}
/*--------------------------------------------------------------------------
* hypre_GMRESSetup
*--------------------------------------------------------------------------*/
int
hypre_GMRESSetup( void *gmres_vdata,
void *A,
void *b,
void *x )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int k_dim = (gmres_data -> k_dim);
int max_iter = (gmres_data -> max_iter);
int (*precond_setup)() = (gmres_data -> precond_setup);
void *precond_data = (gmres_data -> precond_data);
int ierr = 0;
(gmres_data -> A) = A;
/*--------------------------------------------------
* The arguments for NewVector are important to
* maintain consistency between the setup and
* compute phases of matvec and the preconditioner.
*--------------------------------------------------*/
if ((gmres_data -> p) == NULL)
(gmres_data -> p) = hypre_KrylovCreateVectorArray(k_dim+1,x);
if ((gmres_data -> r) == NULL)
(gmres_data -> r) = hypre_KrylovCreateVector(b);
if ((gmres_data -> w) == NULL)
(gmres_data -> w) = hypre_KrylovCreateVector(b);
if ((gmres_data -> matvec_data) == NULL)
(gmres_data -> matvec_data) = hypre_KrylovMatvecCreate(A, x);
precond_setup(precond_data, A, b, x);
/*-----------------------------------------------------
* Allocate space for log info
*-----------------------------------------------------*/
if ((gmres_data -> logging) > 0)
{
if ((gmres_data -> norms) == NULL)
(gmres_data -> norms) = hypre_CTAlloc(double, max_iter + 1);
if ((gmres_data -> log_file_name) == NULL)
(gmres_data -> log_file_name) = "gmres.out.log";
}
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESSolve
*-------------------------------------------------------------------------*/
int
hypre_GMRESSolve(void *gmres_vdata,
void *A,
void *b,
void *x)
{
hypre_GMRESData *gmres_data = gmres_vdata;
int k_dim = (gmres_data -> k_dim);
int min_iter = (gmres_data -> min_iter);
int max_iter = (gmres_data -> max_iter);
int stop_crit = (gmres_data -> stop_crit);
double accuracy = (gmres_data -> tol);
void *matvec_data = (gmres_data -> matvec_data);
void *r = (gmres_data -> r);
void *w = (gmres_data -> w);
void **p = (gmres_data -> p);
int (*precond)() = (gmres_data -> precond);
int *precond_data = (gmres_data -> precond_data);
/* logging variables */
int logging = (gmres_data -> logging);
double *norms = (gmres_data -> norms);
char *log_file_name = (gmres_data -> log_file_name);
/* FILE *fp; */
int ierr = 0;
int i, j, k;
double *rs, **hh, *c, *s;
int iter;
int my_id, num_procs;
double epsilon, gamma, t, r_norm, b_norm;
double epsmac = 1.e-16;
hypre_KrylovCommInfo(A,&my_id,&num_procs);
if (logging > 0)
{
norms = (gmres_data -> norms);
log_file_name = (gmres_data -> log_file_name);
/* fp = fopen(log_file_name,"w"); */
}
/* initialize work arrays */
rs = hypre_CTAlloc(double,k_dim+1);
c = hypre_CTAlloc(double,k_dim);
s = hypre_CTAlloc(double,k_dim);
hh = hypre_CTAlloc(double*,k_dim+1);
for (i=0; i < k_dim+1; i++)
{
hh[i] = hypre_CTAlloc(double,k_dim);
}
hypre_KrylovCopyVector(b,p[0]);
/* compute initial residual */
hypre_KrylovMatvec(matvec_data,-1.0, A, x, 1.0, p[0]);
r_norm = sqrt(hypre_KrylovInnerProd(p[0],p[0]));
b_norm = sqrt(hypre_KrylovInnerProd(b,b));
if (logging > 0)
{
norms[0] = r_norm;
if (my_id == 0)
{
printf("L2 norm of b: %e\n", b_norm);
if (b_norm == 0.0)
printf("Rel_resid_norm actually contains the residual norm\n");
printf("Initial L2 norm of residual: %e\n", r_norm);
}
}
iter = 0;
if (b_norm > 0.0)
{
/* convergence criterion |r_i| <= accuracy*|b| if |b| > 0 */
epsilon = accuracy * b_norm;
}
else
{
/* convergence criterion |r_i| <= accuracy*|r0| if |b| = 0 */
epsilon = accuracy * r_norm;
};
/* convergence criterion |r_i| <= accuracy , absolute residual norm*/
if (stop_crit)
epsilon = accuracy;
while (iter < max_iter)
{
/* initialize first term of hessenberg system */
rs[0] = r_norm;
if (r_norm == 0.0)
{
ierr = 0;
return ierr;
}
if (r_norm <= epsilon && iter >= min_iter)
{
hypre_KrylovCopyVector(b,r);
hypre_KrylovMatvec(matvec_data,-1.0,A,x,1.0,r);
r_norm = sqrt(hypre_KrylovInnerProd(r,r));
if (r_norm <= epsilon)
{
if (logging > 0 && my_id == 0)
printf("Final L2 norm of residual: %e\n\n", r_norm);
break;
}
}
t = 1.0 / r_norm;
hypre_KrylovScaleVector(t,p[0]);
i = 0;
while (i < k_dim && (r_norm > epsilon || iter < min_iter)
&& iter < max_iter)
{
i++;
iter++;
hypre_KrylovClearVector(r);
precond(precond_data, A, p[i-1], r);
hypre_KrylovMatvec(matvec_data, 1.0, A, r, 0.0, p[i]);
/* modified Gram_Schmidt */
for (j=0; j < i; j++)
{
hh[j][i-1] = hypre_KrylovInnerProd(p[j],p[i]);
hypre_KrylovAxpy(-hh[j][i-1],p[j],p[i]);
}
t = sqrt(hypre_KrylovInnerProd(p[i],p[i]));
hh[i][i-1] = t;
if (t != 0.0)
{
t = 1.0/t;
hypre_KrylovScaleVector(t,p[i]);
}
/* done with modified Gram_schmidt and Arnoldi step.
update factorization of hh */
for (j = 1; j < i; j++)
{
t = hh[j-1][i-1];
hh[j-1][i-1] = c[j-1]*t + s[j-1]*hh[j][i-1];
hh[j][i-1] = -s[j-1]*t + c[j-1]*hh[j][i-1];
}
gamma = sqrt(hh[i-1][i-1]*hh[i-1][i-1] + hh[i][i-1]*hh[i][i-1]);
if (gamma == 0.0) gamma = epsmac;
c[i-1] = hh[i-1][i-1]/gamma;
s[i-1] = hh[i][i-1]/gamma;
rs[i] = -s[i-1]*rs[i-1];
rs[i-1] = c[i-1]*rs[i-1];
/* determine residual norm */
hh[i-1][i-1] = c[i-1]*hh[i-1][i-1] + s[i-1]*hh[i][i-1];
r_norm = fabs(rs[i]);
if (logging > 0)
{
norms[iter] = r_norm;
}
}
/* now compute solution, first solve upper triangular system */
rs[i-1] = rs[i-1]/hh[i-1][i-1];
for (k = i-2; k >= 0; k--)
{
t = rs[k];
for (j = k+1; j < i; j++)
{
t -= hh[k][j]*rs[j];
}
rs[k] = t/hh[k][k];
}
/* form linear combination of p's to get solution */
hypre_KrylovCopyVector(p[0],w);
hypre_KrylovScaleVector(rs[0],w);
for (j = 1; j < i; j++)
hypre_KrylovAxpy(rs[j], p[j], w);
hypre_KrylovClearVector(r);
precond(precond_data, A, w, r);
hypre_KrylovAxpy(1.0,r,x);
/* check for convergence, evaluate actual residual */
if (r_norm <= epsilon && iter >= min_iter)
{
hypre_KrylovCopyVector(b,r);
hypre_KrylovMatvec(matvec_data,-1.0,A,x,1.0,r);
r_norm = sqrt(hypre_KrylovInnerProd(r,r));
if (r_norm <= epsilon)
{
if (logging > 0 && my_id == 0)
printf("Final L2 norm of residual: %e\n\n", r_norm);
break;
}
else
{
hypre_KrylovCopyVector(r,p[0]);
i = 0;
}
}
/* compute residual vector and continue loop */
for (j=i ; j > 0; j--)
{
rs[j-1] = -s[j-1]*rs[j];
rs[j] = c[j-1]*rs[j];
}
if (i) hypre_KrylovAxpy(rs[0]-1.0,p[0],p[0]);
for (j=1; j < i+1; j++)
hypre_KrylovAxpy(rs[j],p[j],p[0]);
}
if (logging > 0 && my_id == 0)
{
if (b_norm > 0.0)
{printf("=============================================\n\n");
printf("Iters resid.norm conv.rate rel.res.norm\n");
printf("----- ------------ ---------- ------------\n");
for (j = 1; j <= iter; j++)
{
printf("% 5d %e %f %e\n", j, norms[j],norms[j]/norms[j-1],
norms[j]/b_norm);
}
printf("\n\n"); }
else
{printf("=============================================\n\n");
printf("Iters resid.norm conv.rate\n");
printf("----- ------------ ----------\n");
for (j = 1; j <= iter; j++)
{
printf("% 5d %e %f\n", j, norms[j],norms[j]/norms[j-1]);
}
printf("\n\n"); };
}
(gmres_data -> num_iterations) = iter;
if (b_norm > 0.0)
(gmres_data -> rel_residual_norm) = r_norm/b_norm;
if (b_norm == 0.0)
(gmres_data -> rel_residual_norm) = r_norm;
if (iter >= max_iter && r_norm > epsilon) ierr = 1;
hypre_TFree(c);
hypre_TFree(s);
hypre_TFree(rs);
for (i=0; i < k_dim+1; i++)
{
hypre_TFree(hh[i]);
}
hypre_TFree(hh);
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESSetKDim
*--------------------------------------------------------------------------*/
int
hypre_GMRESSetKDim( void *gmres_vdata,
int k_dim )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int ierr = 0;
(gmres_data -> k_dim) = k_dim;
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESSetTol
*--------------------------------------------------------------------------*/
int
hypre_GMRESSetTol( void *gmres_vdata,
double tol )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int ierr = 0;
(gmres_data -> tol) = tol;
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESSetMinIter
*--------------------------------------------------------------------------*/
int
hypre_GMRESSetMinIter( void *gmres_vdata,
int min_iter )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int ierr = 0;
(gmres_data -> min_iter) = min_iter;
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESSetMaxIter
*--------------------------------------------------------------------------*/
int
hypre_GMRESSetMaxIter( void *gmres_vdata,
int max_iter )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int ierr = 0;
(gmres_data -> max_iter) = max_iter;
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESSetStopCrit
*--------------------------------------------------------------------------*/
int
hypre_GMRESSetStopCrit( void *gmres_vdata,
double stop_crit )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int ierr = 0;
(gmres_data -> stop_crit) = stop_crit;
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESSetPrecond
*--------------------------------------------------------------------------*/
int
hypre_GMRESSetPrecond( void *gmres_vdata,
int (*precond)(),
int (*precond_setup)(),
void *precond_data )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int ierr = 0;
(gmres_data -> precond) = precond;
(gmres_data -> precond_setup) = precond_setup;
(gmres_data -> precond_data) = precond_data;
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESGetPrecond
*--------------------------------------------------------------------------*/
int
hypre_GMRESGetPrecond( void *gmres_vdata,
HYPRE_Solver *precond_data_ptr )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int ierr = 0;
*precond_data_ptr = (HYPRE_Solver)(gmres_data -> precond_data);
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESSetLogging
*--------------------------------------------------------------------------*/
int
hypre_GMRESSetLogging( void *gmres_vdata,
int logging)
{
hypre_GMRESData *gmres_data = gmres_vdata;
int ierr = 0;
(gmres_data -> logging) = logging;
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESGetNumIterations
*--------------------------------------------------------------------------*/
int
hypre_GMRESGetNumIterations( void *gmres_vdata,
int *num_iterations )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int ierr = 0;
*num_iterations = (gmres_data -> num_iterations);
return ierr;
}
/*--------------------------------------------------------------------------
* hypre_GMRESGetFinalRelativeResidualNorm
*--------------------------------------------------------------------------*/
int
hypre_GMRESGetFinalRelativeResidualNorm( void *gmres_vdata,
double *relative_residual_norm )
{
hypre_GMRESData *gmres_data = gmres_vdata;
int ierr = 0;
*relative_residual_norm = (gmres_data -> rel_residual_norm);
return ierr;
}