KMeans.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#include "base-precomp.h"  // Precompiled headers

#include <mrpt/math/kmeans.h>

// This file is just a stub for the k-means++ library so MRPT users don't need
//  to include those headers too.

// Include the kmeans++ library, by David Arthur (darthur@gmail.com), 2009:
#include "kmeans++/KMeans.h"

using namespace std;
using namespace mrpt;
using namespace mrpt::math;
using namespace mrpt::utils;

namespace mrpt
{
namespace math
{
namespace detail
{
/* -------------------------------------------
                                 internal_kmeans
   ------------------------------------------- */
template <>
double internal_kmeans<double>(
        const bool use_kmeansplusplus_method, const size_t nPoints, const size_t k,
        const size_t dims, const double* points, const size_t attempts,
        double* out_center, int* out_assignments)
{
        MRPT_UNUSED_PARAM(use_kmeansplusplus_method);
        return RunKMeans(
                nPoints, k, dims, const_cast<double*>(points), attempts, out_center,
                out_assignments);
}

template <>
double internal_kmeans<float>(
        const bool use_kmeansplusplus_method, const size_t nPoints, const size_t k,
        const size_t dims, const float* points, const size_t attempts,
        float* out_center, int* out_assignments)
{
        MRPT_UNUSED_PARAM(use_kmeansplusplus_method);
        std::vector<double> points_d(nPoints * dims);
        std::vector<double> centers_d(k * dims);
        // Convert: float -> double
        for (size_t i = 0; i < nPoints * dims; i++) points_d[i] = double(points[i]);

        const double ret = RunKMeans(
                nPoints, k, dims, &points_d[0], attempts, &centers_d[0],
                out_assignments);

        // Convert: double -> float
        if (out_center)
                for (size_t i = 0; i < k * dims; i++)
                        out_center[i] = float(centers_d[i]);

        return ret;
}
}
}
}