|| || || || || || || ||

---

VectorQuantize.h

Go to the documentation of this file.

#ifndef Impala_Core_Matrix_VectorQuantize_h
#define Impala_Core_Matrix_VectorQuantize_h

#include "Core/Matrix/MatFunc.h"
#include "Core/Matrix/MatNorm2Dist.h"
#include "Core/Matrix/Mat.h"

namespace Impala
{
namespace Core
{
namespace Matrix
{


Mat* VectorQuantizeX(Mat* a, Mat* codebook)
{
    Mat* distances = 0;
#ifdef CUDA
    if(Link::Cuda::CudaUsed())
    {
        //distances = Link::Cuda::MatNorm2DistTransposed(a, codebook);
        return Link::Cuda::MatCodebookAssignHard(a, codebook);
    }
    else
#endif
    {
        distances = MatNorm2DistTransposed(a,codebook);
        Mat* res = MatCreate<Mat>(MatNrRow(a), 2);
        for(int vj = 0; vj < MatNrRow(a); vj++)
        {
            Real64 bestDistance = 999999999.0;
            int    bestIndex = 0;
            for(int i = 0; i < MatNrRow(codebook); i++)
            {
                Real64 value = *MatE(distances, vj, i);
                if(value < bestDistance)
                {
                    bestDistance = value;
                    bestIndex = i;
                }
            }
            *MatE(res, vj, 0) = bestIndex;
            *MatE(res, vj, 1) = bestDistance;
        }
        delete distances;
        return res;
    }
}


Mat* VectorQuantize(Mat* data, Mat* codebook)
{
    Timer vqTimer;
    int step = 10000;
    Mat* res = MatCreate<Mat>(MatNrRow(data), 2);
// OpenMP support is possible, but do limit the step size or memory usage will explode
//#pragma omp parallel for schedule(static)
    for(int i = 0; i < MatNrRow(data); i += step)
    {
        int s = MatNrRow(data) - i;
        if(step < s) s = step;

        Mat* partial = MatCreate<Mat>(s, MatNrCol(data), MatE(data, i, 0), true);
        //std::cout << "QuantizePart" << i << " start " << vqTimer.SplitTimeStr() << std::endl;
        Mat* temp = VectorQuantizeX(partial, codebook);
        //std::cout << "QuantizePart" << i << " vq'd " << vqTimer.SplitTimeStr() << std::endl;
        for(int j = 0; j < s; j++)
        {
            *MatE(res, i + j, 0) = *MatE(temp, j, 0);
            *MatE(res, i + j, 1) = *MatE(temp, j, 1);
        }
        delete temp;
        delete partial;
    }
    return res;
}


} // namespace Matrix
} // namespace Core
} // namespace Impala

#endif

---