void oskmeans::clusterize()
{
// initialize.
initialize();
if (_snippets.empty())
return;
// clustering.
while (!stopping_criterion())
{
#ifdef DEBUG
std::cerr << "[Debug]:clusterize, iteration #" << _iterations << std::endl;
#endif
for (short c=0; c<_K; c++)
{
// clear the cluster.
_clusters[c].clear();
}
// clear the garbage cluster.
_garbage_cluster.clear();
// iterates points and associate each of them with a cluster.
hash_map<uint32_t,hash_map<uint32_t,float,id_hash_uint>*,id_hash_uint>::const_iterator hit
= _points.begin();
while (hit!=_points.end())
{
float learning_rate = oskmeans::_nu0*pow((oskmeans::_nuf/oskmeans::_nu0),_t/static_cast<float>(_points.size()*oskmeans::_niterations));
#ifdef DEBUG
std::cerr << "learning rate: " << learning_rate << std::endl;
#endif
// find closest cluster to this point.
short cl = assign_cluster((*hit).first,(*hit).second);
// recomputation of centroids/medoids.
if (cl != -1)
{
float cl_norm = 0.0;
recompute_centroid(learning_rate,&_clusters[cl]._c,(*hit).second,cl_norm);
normalize_centroid(&_clusters[cl]._c,cl_norm);
}
++hit;
_t++;
}
// count iteration.
_iterations++;
}
}
/**Function********************************************************************
Synopsis [Get new variable-order by simulated annealing algorithm.]
Description [Get x, y by random selection. Choose either
exchange or jump randomly. In case of jump, choose between jump_up
and jump_down randomly. Do exchange or jump and get optimal case.
Loop until there is no improvement or temperature reaches
minimum. Returns 1 in case of success; 0 otherwise.]
SideEffects [None]
SeeAlso []
******************************************************************************/
int
cuddAnnealing(
DdManager * table,
int lower,
int upper)
{
int nvars;
int size;
int x,y;
int result;
int c1, c2, c3, c4;
int BestCost;
int *BestOrder;
double NewTemp, temp;
double rand1;
int innerloop, maxGen;
int ecount, ucount, dcount;
nvars = upper - lower + 1;
result = cuddSifting(table,lower,upper);
#ifdef DD_STATS
(void) fprintf(table->out,"\n");
#endif
if (result == 0) return(0);
size = table->keys - table->isolated;
/* Keep track of the best order. */
BestCost = size;
BestOrder = ALLOC(int,nvars);
if (BestOrder == NULL) {
table->errorCode = CUDD_MEMORY_OUT;
return(0);
}
copyOrder(table,BestOrder,lower,upper);
temp = BETA * size;
maxGen = (int) (MAXGEN_RATIO * nvars);
c1 = size + 10;
c2 = c1 + 10;
c3 = size;
c4 = c2 + 10;
ecount = ucount = dcount = 0;
while (!stopping_criterion(c1, c2, c3, c4, temp)) {
#ifdef DD_STATS
(void) fprintf(table->out,"temp=%f\tsize=%d\tgen=%d\t",
temp,size,maxGen);
tosses = acceptances = 0;
#endif
for (innerloop = 0; innerloop < maxGen; innerloop++) {
/* Choose x, y randomly. */
x = (int) Cudd_Random() % nvars;
do {
y = (int) Cudd_Random() % nvars;
} while (x == y);
x += lower;
y += lower;
if (x > y) {
int tmp = x;
x = y;
y = tmp;
}
/* Choose move with roulette wheel. */
rand1 = random_generator();
if (rand1 < EXC_PROB) {
result = ddExchange(table,x,y,temp); /* exchange */
ecount++;
#if 0
(void) fprintf(table->out,
"Exchange of %d and %d: size = %d\n",
x,y,table->keys - table->isolated);
#endif
} else if (rand1 < EXC_PROB + JUMP_UP_PROB) {
result = ddJumpingAux(table,y,x,y,temp); /* jumping_up */
ucount++;
#if 0
(void) fprintf(table->out,
"Jump up of %d to %d: size = %d\n",
y,x,table->keys - table->isolated);
#endif
} else {
result = ddJumpingAux(table,x,x,y,temp); /* jumping_down */
dcount++;
#if 0
(void) fprintf(table->out,
"Jump down of %d to %d: size = %d\n",
x,y,table->keys - table->isolated);
#endif
}
if (!result) {
FREE(BestOrder);
return(0);
}
size = table->keys - table->isolated; /* keep current size */
if (size < BestCost) { /* update best order */
BestCost = size;
copyOrder(table,BestOrder,lower,upper);
}
}
c1 = c2;
c2 = c3;
c3 = c4;
c4 = size;
NewTemp = ALPHA * temp;
if (NewTemp >= 1.0) {
maxGen = (int)(log(NewTemp) / log(temp) * maxGen);
}
temp = NewTemp; /* control variable */
#ifdef DD_STATS
(void) fprintf(table->out,"uphill = %d\taccepted = %d\n",
tosses,acceptances);
fflush(table->out);
#endif
}
result = restoreOrder(table,BestOrder,lower,upper);
FREE(BestOrder);
if (!result) return(0);
#ifdef DD_STATS
fprintf(table->out,"#:N_EXCHANGE %8d : total exchanges\n",ecount);
fprintf(table->out,"#:N_JUMPUP %8d : total jumps up\n",ucount);
fprintf(table->out,"#:N_JUMPDOWN %8d : total jumps down",dcount);
#endif
return(1);
} /* end of cuddAnnealing */
