void KCleaf::sampleCtr( // sample from leaf node
KMpoint c, // the sampled point (returned)
KMorthRect &bnd_box) // bounding box for current node
{
int ri = kmRanInt(n_data); // generate random index
kmCopyPt(kcDim, kcPoints[bkt[ri]], c); // copy to destination
}
void KMdata::sampleCtrs( // sample points randomly
KMcenterArray sample, // where to store sample
int k, // number of points to sample
bool allowDuplicate) // sample with replacement?
{
if (!allowDuplicate) // duplicates not allowed
assert(k <= nPts); // can't do more than nPts
int* sampIdx = new int[k]; // allocate index array
for (int i = 0; i < k; i++) { // sample each point of sample
int ri = kmRanInt(nPts); // random index in pts
if (!allowDuplicate) { // duplicates not allowed?
bool dupFound; // duplicate found flag
do { // repeat until successful
dupFound = false;
for (int j = 0; j < i; j++) { // search for duplicates
if (sampIdx[j] == ri) { // duplicate found
dupFound = true;
ri = kmRanInt(nPts); // try again
break;
}
}
} while (dupFound);
}
kmCopyPt(dim, pts[ri], sample[i]); // copy sample point
sampIdx[i] = ri; // save index
}
delete [] sampIdx;
}
//----------------------------------------------------------------------
// swapOneCenter
// Swaps one center point with a sample point. Optionally we make
// sure that the new point is not a duplicate of any of the centers
// (including the point being replaced).
//----------------------------------------------------------------------
void KMfilterCenters::swapOneCenter( // swap one center
bool allowDuplicate) // allow duplicate centers
{
int rj = kmRanInt(kCtrs); // index of center to replace
int dim = getDim();
KMpoint p = kmAllocPt(dim); // alloc replacement point
pts->sampleCtr(p); // sample a replacement
if (!allowDuplicate) { // duplicates not allowed?
bool dupFound; // was a duplicate found?
do { // repeat until successful
dupFound = false;
for (int j = 0; j < kCtrs; j++) { // search for duplicates
if (kmEqualPts(dim, p, ctrs[j])) {
dupFound = true;
pts->sampleCtr(p); // try again
break;
}
}
} while (dupFound);
}
kmCopyPt(dim, p, ctrs[rj]); // copy sampled point
if (kmStatLev >= STEP) { // output swap info
*kmOut << "\tswapping: ";
kmPrintPt(p, getDim(), true);
*kmOut << "<-->Center[" << rj << "]\n";
}
kmDeallocPt(p); // deallocate point storage
invalidate(); // distortions now invalid
}
void KMdata::sampleCtr( // sample a center point
KMcenter sample) // where to store sample
{
int ri = kmRanInt(nPts); // generate random index
kmCopyPt(dim, pts[ri], sample); // copy to destination
}
