doc/charm++/kmeans.cpp

   1 // One instance is created and called on each PE
   2 void KMeansGroup::cluster()
   3 {
   4   CLUSTERS::Write w = clusters.getInitialWrite();
   5   if (initSeed != -1) writePosition(w, initSeed);
   6
   7   // Put the array in Read mode
   8   CLUSTERS::Read r = w.syncToRead();
   9
  10   do {
  11     // Each PE finds the seed closest to itself
  12     double minDistance = distance(r, curSeed);
  13
  14     for (int i = 0; i < numClusters; ++i) {
  15       double d = distance(r, i);
  16       if(d < minDistance) {
  17         minDistance = d;
  18         newSeed = i;
  19       }
  20     }
  21
  22     // Put the array in Accumulate mode,
  23     // excluding the current value
  24     CLUSTERS::Accum a = r.syncToExcAccum();
  25     // Each PE adds itself to its new seed
  26     for (int i = 0; i < numMetrics; ++i)
  27       a(newSeed, i) += metrics[i];
  28
  29     // Update membership and change count
  30     a(newSeed, numMetrics) += 1;
  31     if (curSeed != newSeed)
  32       a(0, numMetrics+1) += 1;
  33     curSeed = newSeed;
  34
  35     // Put the array in Read mode
  36     r = a.syncToRead();
  37   } while(r(0, numMetrics+1) > 0);
  38 }