void eigs_reorder (int d, float * eigval, float * eigvec, int criterion)
{
int i;
int * perm = ivec_new (d);
float * eigvalst = fvec_new (d);
float * eigvecst = fvec_new (d * d);
fvec_sort_index (eigval, d, perm);
if (criterion)
for (i = 0 ; i < d / 2 ; i++) {
int tmp = perm[i];
perm[i] = perm[d - 1 - i];
perm[d - 1 - i] = tmp;
}
for (i = 0 ; i < d ; i++) {
eigvalst[i] = eigval[perm[i]];
memcpy (eigvecst + i * d, eigvec + perm[i] * d, sizeof (*eigvecst) * d);
}
memcpy (eigval, eigvalst, d * sizeof (*eigval));
memcpy (eigvec, eigvecst, d * d * sizeof (*eigvec));
free (eigvalst);
free (eigvecst);
free (perm);
}
void knn_reorder_shortlist(int n, int nb, int d, int k,
const float *b, const float *v,
int *assign,
float *dists)
{
float *subb=fvec_new(k*d);
float *diststmp=fvec_new(k);
int *perm=ivec_new(k);
int *assigntmp=ivec_new(k);
int i,j;
for(i=0;i<n;i++) {
int *assigni=assign+i*k;
float *disti=dists+i*k;
int ki ;
if(1) {
for(j=0;j<k;j++) {
if(assigni[j]<0) break;
memcpy(subb+j*d,b+assigni[j]*d,sizeof(*subb)*d);
}
ki=j;
} else {
for(j=0;j<k;j++)
if(assigni[j]<0) break;
ki=j;
ivec_sort(assigni,ki); /* to improve access locality */
for(j=0;j<ki;j++) {
memcpy(subb+j*d,b+assigni[j]*(long) d,sizeof(*subb)*d);
}
}
compute_distances_1(d,ki,v+i*d,subb,diststmp);
fvec_sort_index(diststmp,ki,perm);
memcpy(assigntmp,assigni,sizeof(*assigni)*ki);
for(j=0;j<ki;j++) {
disti[j]=diststmp[perm[j]];
assigni[j]=assigntmp[perm[j]];
}
}
free(assigntmp);
free(diststmp);
free(subb);
free(perm);
}
