Example #1
0
 void InfoBitRanker::setMaskBits(RDKit::INT_VECT &maskBits) {
   delete dp_maskBits;
   dp_maskBits = new ExplicitBitVect(d_dims);
   for (RDKit::INT_VECT_CI bi = maskBits.begin();
        bi != maskBits.end(); ++bi) {
     dp_maskBits->setBit(*bi);
   }
 }
  RDKit::VECT_INT_VECT HierarchicalClusterPicker::cluster(const double *distMat,
                                                          unsigned int poolSize,
                                                          unsigned int pickSize) const {
    PRECONDITION(distMat, "Invalid Distance Matrix");
    PRECONDITION((poolSize >= pickSize),
                 "pickSize cannot be larger than the poolSize");

    // Do the clustering 
    long int method = (long int)d_method;
    long int len = poolSize*(poolSize-1);
    long int *ia = (long int *)calloc(poolSize, sizeof(long int));
    long int *ib = (long int *)calloc(poolSize, sizeof(long int));
    real *crit = (real *)calloc(poolSize,sizeof(real));
    CHECK_INVARIANT(ia,"failed to allocate memory");
    CHECK_INVARIANT(ib,"failed to allocate memory");
    CHECK_INVARIANT(crit,"failed to allocate memory");
    long int poolSize2=static_cast<long int>(poolSize);
    
    distdriver_(&poolSize2, // number of items in the pool
                &len, // number of entries in the distance matrix
                (real *)distMat, // distance matrix
                &method, // the clustering method (ward, slink etc.)
                ia, // int vector with clustering history
                ib, // one more clustering history matrix
                crit // I believe this is a vector the difference in heights of two clusters
                );

    // we have the clusters now merge then until the number of clusters is same
    // as the number of picks we need
    // before we do that a bit of explanation on the vectors "ia" and "ib"
    //  - We with each item in the pool as an individual cluster
    //  - then we use the vectors ia and ib to merge them.
    //     ia and ib provides the ids of the clusters that need to be merged
    //     it is assumed that when a cluster ia[j] is merged with ib[j] 
    //     ia[j] is replaced by the new cluster in the cluster list
    // 
    RDKit::VECT_INT_VECT clusters;
    for (unsigned int i = 0; i < poolSize; i++) {
      RDKit::INT_VECT cls;
      cls.push_back(i);
      clusters.push_back(cls);
    }

    // do the merging, each round of of this loop eleminates one cluster
    RDKit::INT_VECT removed;
    for (unsigned int i = 0; i < (poolSize - pickSize); i++) {
      int cx1 = ia[i] - 1;
      int cx2 = ib[i] - 1;

      // add the items from cluster cx2 to cx1
      // REVIEW: merge function???
      for (RDKit::INT_VECT_CI cx2i = clusters[cx2].begin(); cx2i != clusters[cx2].end(); cx2i++) {
        clusters[cx1].push_back(*cx2i);
      }
      
      // mark the second cluster as removed
      removed.push_back(cx2);
    }
    free(ia);
    free(ib);
    free(crit);

    // sort removed so that looping will be easier later
    std::sort(removed.begin(), removed.end());

    //some error checking here, uniqueify removed and the vector should not changed
    // REVIEW can we put this inside a #ifdef DEBUG?
    RDKit::INT_VECT_CI nEnd = std::unique(removed.begin(), removed.end());
    CHECK_INVARIANT(nEnd == removed.end(), "Somehow there are duplicates in the list of removed clusters");

    RDKit::VECT_INT_VECT res;
    unsigned int j = 0;
    for (unsigned int i = 0; i < poolSize; i++) {
      if (static_cast<int>(i) == removed[j]) {
        j++;
        continue;
      }
      res.push_back(clusters[i]);
    }
    return res;
  }