RandomCARTree.cpp

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/*
 * Copyright (c) The Shogun Machine Learning Toolbox
 * Written (w) 2014 Parijat Mazumdar
 * All rights reserved.
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#include <shogun/multiclass/tree/RandomCARTree.h>
#include <shogun/mathematics/Math.h>

using namespace shogun;

CRandomCARTree::CRandomCARTree()
: CCARTree()
{
    init();
}

CRandomCARTree::~CRandomCARTree()
{
}

void CRandomCARTree::set_feature_subset_size(int32_t size)
{
    REQUIRE(size>0, "Subset size should be greater than 0. %d supplied!\n",size)
    m_randsubset_size=size;
}

int32_t CRandomCARTree::compute_best_attribute(const SGMatrix<float64_t>& mat, const SGVector<float64_t>& weights, CLabels* labels,
    SGVector<float64_t>& left, SGVector<float64_t>& right, SGVector<bool>& is_left_final, int32_t &num_missing_final, int32_t &count_left,
    int32_t &count_right, int32_t subset_size, const SGVector<index_t>& active_indices)

{
    int32_t num_feats;
    if(m_pre_sort)
        num_feats=mat.num_cols;
    else
        num_feats=mat.num_rows;
    
    // if subset size is not set choose sqrt(num_feats) by default
    if (m_randsubset_size==0)
        m_randsubset_size=CMath::sqrt(mat.num_rows-0.f);
    subset_size=m_randsubset_size;
    
    REQUIRE(subset_size<=num_feats, "The Feature subset size(set %d) should be less than"
    " or equal to the total number of features(%d here).\n",subset_size,num_feats)

    return CCARTree::compute_best_attribute(mat,weights,labels,left,right,is_left_final,num_missing_final,count_left,count_right,subset_size, active_indices);

}

void CRandomCARTree::init()
{
    m_randsubset_size=0;

    SG_ADD(&m_randsubset_size,"m_randsubset_size", "random features subset size", MS_NOT_AVAILABLE);
}