libigl/include/igl/mode.cpp

// This file is part of libigl, a simple c++ geometry processing library.
// 
// Copyright (C) 2013 Alec Jacobson <[email protected]>
// 
// This Source Code Form is subject to the terms of the Mozilla Public License 
// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
// obtain one at http://mozilla.org/MPL/2.0/.
#include "mode.h"

// Implementation 
#include <vector>

template <typename T>
IGL_INLINE void igl::mode(
  const Eigen::Matrix<T,Eigen::Dynamic,Eigen::Dynamic> & X,
  const int d, 
  Eigen::Matrix<T,Eigen::Dynamic,1> & M)
{
  assert(d==1 || d==2);
  int m = X.rows();
  int n = X.cols();
  M.resize((d==1)?n:m,1);
  for(int i = 0;i<((d==2)?m:n);i++)
  {
    std::vector<int> counts(((d==2)?n:m),0);
    for(int j = 0;j<((d==2)?n:m);j++)
    {
      T v = (d==2)?X(i,j):X(j,i);
      for(int k = 0;k<((d==2)?n:m);k++)
      {
        T u = (d==2)?X(i,k):X(k,i);
        if(v == u)
        {
          counts[k]++;
        }
      }
    }
    assert(counts.size() > 0);
    int max_count = -1;
    int max_count_j = -1;
    int j =0;
    for(std::vector<int>::iterator it = counts.begin();it<counts.end();it++)
    {
      if(max_count < *it)
      {
        max_count = *it;
        max_count_j = j;
      }
      j++;
    }
    M(i,0) = (d==2)?X(i,max_count_j):X(max_count_j,i);
  }
}

#ifdef IGL_STATIC_LIBRARY
// Explicit template instantiation
// generated by autoexplicit.sh
template void igl::mode<double>(Eigen::Matrix<double, -1, -1, 0, -1, -1> const&, int, Eigen::Matrix<double, -1, 1, 0, -1, 1>&);
// generated by autoexplicit.sh
template void igl::mode<int>(Eigen::Matrix<int, -1, -1, 0, -1, -1> const&, int, Eigen::Matrix<int, -1, 1, 0, -1, 1>&);
#endif