     int n_gpus;
     cudaGetDeviceCount(&n_gpus);
 //TODO
-    n_gpus = 1;
+//    n_gpus = 1;
 
     if (n_gpus == 0) {
       std::cerr << "error: no CUDA-compatible GPUs found" << std::endl;



#define BSIZE 128
#define N_STREAMS 1

namespace Clustering {
namespace Density {

      cudaMemset(d_in_radius[i_stream]
               , 0
               , sizeof(float) * n_rows * n_radii);
//TODO
      // prune range for faster computation
      // (using largest radius in first dimension)
//      auto min_max_box = Clustering::Tools::min_max_box(blimits
//                                                      , coords[i*n_cols]
//                                                      , radii[0]);
//      unsigned int offset = min_max_box.first * BSIZE;
//      unsigned int rng = (min_max_box.second-min_max_box.first+1);
      unsigned int rng = Tools::min_multiplicator(n_rows, BSIZE);
      unsigned int offset = 0;
      in_radius <<< rng
                  , BSIZE
                  , 0
