MulticlassSVM.cpp

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/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * Written (W) 1999-2009 Soeren Sonnenburg
 * Copyright (C) 1999-2009 Fraunhofer Institute FIRST and Max-Planck-Society
 */

#include <shogun/lib/common.h>
#include <shogun/io/SGIO.h>
#include <shogun/multiclass/MulticlassSVM.h>
#include <shogun/multiclass/MulticlassOneVsRestStrategy.h>

using namespace shogun;

CMulticlassSVM::CMulticlassSVM()
    :CKernelMulticlassMachine(new CMulticlassOneVsRestStrategy(), NULL, new CSVM(0), NULL), m_C(0)
{
    init();
}

CMulticlassSVM::CMulticlassSVM(CMulticlassStrategy *strategy)
    :CKernelMulticlassMachine(strategy, NULL, new CSVM(0), NULL), m_C(0)
{
    init();
}

CMulticlassSVM::CMulticlassSVM(
    CMulticlassStrategy *strategy, float64_t C, CKernel* k, CLabels* lab)
    : CKernelMulticlassMachine(strategy, k, new CSVM(C, k, lab), lab), m_C(C)
{
    init();
}

CMulticlassSVM::~CMulticlassSVM()
{
}

void CMulticlassSVM::init()
{
    SG_ADD(&m_C, "C", "C regularization constant",MS_AVAILABLE);
}

bool CMulticlassSVM::create_multiclass_svm(int32_t num_classes)
{
    if (num_classes>0)
    {
        int32_t num_svms=m_multiclass_strategy->get_num_machines();

        m_machines->reset_array();
        for (index_t i=0; i<num_svms; ++i)
            m_machines->push_back(NULL);

        return true;
    }
    return false;
}

bool CMulticlassSVM::set_svm(int32_t num, CSVM* svm)
{
    if (m_machines->get_num_elements()>0 && m_machines->get_num_elements()>num && num>=0 && svm)
    {
        m_machines->set_element(svm, num);
        return true;
    }
    return false;
}

bool CMulticlassSVM::init_machines_for_apply(CFeatures* data)
{
    if (is_data_locked())
    {
        SG_ERROR("CKernelMachine::apply(CFeatures*) cannot be called when "
                "data_lock was called before. Call data_unlock to allow.");
    }

    if (!m_kernel)
        SG_ERROR("No kernel assigned!\n");

    CFeatures* lhs=m_kernel->get_lhs();
    if (!lhs && m_kernel->get_kernel_type()!=K_COMBINED)
        SG_ERROR("%s: No left hand side specified\n", get_name());

    if (m_kernel->get_kernel_type()!=K_COMBINED && !lhs->get_num_vectors())
    {
        SG_ERROR("%s: No vectors on left hand side (%s). This is probably due to"
                " an implementation error in %s, where it was forgotten to set "
                "the data (m_svs) indices\n", get_name(),
                data->get_name());
    }

    if (data && m_kernel->get_kernel_type()!=K_COMBINED)
        m_kernel->init(lhs, data);
    SG_UNREF(lhs);

    for (int32_t i=0; i<m_machines->get_num_elements(); i++)
    {
        CSVM *the_svm = (CSVM *)m_machines->get_element(i);
        ASSERT(the_svm);
        the_svm->set_kernel(m_kernel);
        SG_UNREF(the_svm);
    }

    return true;
}

bool CMulticlassSVM::load(FILE* modelfl)
{
    bool result=true;
    char char_buffer[1024];
    int32_t int_buffer;
    float64_t double_buffer;
    int32_t line_number=1;
    int32_t svm_idx=-1;

    SG_SET_LOCALE_C;

    if (fscanf(modelfl,"%15s\n", char_buffer)==EOF)
        SG_ERROR( "error in svm file, line nr:%d\n", line_number);
    else
    {
        char_buffer[15]='\0';
        if (strcmp("%MultiClassSVM", char_buffer)!=0)
            SG_ERROR( "error in multiclass svm file, line nr:%d\n", line_number);

        line_number++;
    }

    int_buffer=0;
    if (fscanf(modelfl," num_classes=%d; \n", &int_buffer) != 1)
        SG_ERROR( "error in svm file, line nr:%d\n", line_number);

    if (!feof(modelfl))
        line_number++;

    if (int_buffer < 2)
        SG_ERROR("less than 2 classes - how is this multiclass?\n");

    create_multiclass_svm(int_buffer);

    int_buffer=0;
    if (fscanf(modelfl," num_svms=%d; \n", &int_buffer) != 1)
        SG_ERROR( "error in svm file, line nr:%d\n", line_number);

    if (!feof(modelfl))
        line_number++;

    if (m_machines->get_num_elements() != int_buffer)
        SG_ERROR("Mismatch in number of svms: m_num_svms=%d vs m_num_svms(file)=%d\n", m_machines->get_num_elements(), int_buffer);

    if (fscanf(modelfl," kernel='%s'; \n", char_buffer) != 1)
        SG_ERROR( "error in svm file, line nr:%d\n", line_number);

    if (!feof(modelfl))
        line_number++;

    for (int32_t n=0; n<m_machines->get_num_elements(); n++)
    {
        svm_idx=-1;
        if (fscanf(modelfl,"\n%4s %d of %d\n", char_buffer, &svm_idx, &int_buffer)==EOF)
        {
            result=false;
            SG_ERROR( "error in svm file, line nr:%d\n", line_number);
        }
        else
        {
            char_buffer[4]='\0';
            if (strncmp("%SVM", char_buffer, 4)!=0)
            {
                result=false;
                SG_ERROR( "error in svm file, line nr:%d\n", line_number);
            }

            if (svm_idx != n)
                SG_ERROR("svm index mismatch n=%d, n(file)=%d\n", n, svm_idx);

            line_number++;
        }

        int_buffer=0;
        if (fscanf(modelfl,"numsv%d=%d;\n", &svm_idx, &int_buffer) != 2)
            SG_ERROR( "error in svm file, line nr:%d\n", line_number);

        if (svm_idx != n)
            SG_ERROR("svm index mismatch n=%d, n(file)=%d\n", n, svm_idx);

        if (!feof(modelfl))
            line_number++;

        SG_INFO("loading %ld support vectors for svm %d\n",int_buffer, svm_idx);
        CSVM* svm=new CSVM(int_buffer);

        double_buffer=0;

        if (fscanf(modelfl," b%d=%lf; \n", &svm_idx, &double_buffer) != 2)
            SG_ERROR( "error in svm file, line nr:%d\n", line_number);

        if (svm_idx != n)
            SG_ERROR("svm index mismatch n=%d, n(file)=%d\n", n, svm_idx);

        if (!feof(modelfl))
            line_number++;

        svm->set_bias(double_buffer);

        if (fscanf(modelfl,"alphas%d=[\n", &svm_idx) != 1)
            SG_ERROR( "error in svm file, line nr:%d\n", line_number);

        if (svm_idx != n)
            SG_ERROR("svm index mismatch n=%d, n(file)=%d\n", n, svm_idx);

        if (!feof(modelfl))
            line_number++;

        for (int32_t i=0; i<svm->get_num_support_vectors(); i++)
        {
            double_buffer=0;
            int_buffer=0;

            if (fscanf(modelfl,"\t[%lf,%d]; \n", &double_buffer, &int_buffer) != 2)
                SG_ERROR( "error in svm file, line nr:%d\n", line_number);

            if (!feof(modelfl))
                line_number++;

            svm->set_support_vector(i, int_buffer);
            svm->set_alpha(i, double_buffer);
        }

        if (fscanf(modelfl,"%2s", char_buffer) == EOF)
        {
            result=false;
            SG_ERROR( "error in svm file, line nr:%d\n", line_number);
        }
        else
        {
            char_buffer[3]='\0';
            if (strcmp("];", char_buffer)!=0)
            {
                result=false;
                SG_ERROR( "error in svm file, line nr:%d\n", line_number);
            }
            line_number++;
        }

        set_svm(n, svm);
    }

    svm_proto()->svm_loaded=result;

    SG_RESET_LOCALE;
    return result;
}

bool CMulticlassSVM::save(FILE* modelfl)
{
    SG_SET_LOCALE_C;

    if (!m_kernel)
        SG_ERROR("Kernel not defined!\n");

    if (m_machines->get_num_elements()<1)
        SG_ERROR("Multiclass SVM not trained!\n");

    SG_INFO( "Writing model file...");
    fprintf(modelfl,"%%MultiClassSVM\n");
    fprintf(modelfl,"num_classes=%d;\n", m_multiclass_strategy->get_num_classes());
    fprintf(modelfl,"num_svms=%d;\n", m_machines->get_num_elements());
    fprintf(modelfl,"kernel='%s';\n", m_kernel->get_name());

    for (int32_t i=0; i<m_machines->get_num_elements(); i++)
    {
        CSVM* svm=get_svm(i);
        ASSERT(svm);
        fprintf(modelfl,"\n%%SVM %d of %d\n", i, m_machines->get_num_elements()-1);
        fprintf(modelfl,"numsv%d=%d;\n", i, svm->get_num_support_vectors());
        fprintf(modelfl,"b%d=%+10.16e;\n",i,svm->get_bias());

        fprintf(modelfl, "alphas%d=[\n", i);

        for(int32_t j=0; j<svm->get_num_support_vectors(); j++)
        {
            fprintf(modelfl,"\t[%+10.16e,%d];\n",
                    svm->get_alpha(j), svm->get_support_vector(j));
        }

        fprintf(modelfl, "];\n");
    }

    SG_RESET_LOCALE;
    SG_DONE();
    return true ;
}