KernelMulticlassMachine.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) 2012 Chiyuan Zhang
 * Written (W) 2012 Heiko Strathmann
 * Copyright (C) 2012 Chiyuan Zhang
 */

#include <shogun/lib/Set.h>
#include <shogun/machine/KernelMulticlassMachine.h>

using namespace shogun;

void CKernelMulticlassMachine::store_model_features()
{
    CKernel *kernel= m_kernel;
    if (!kernel)
        SG_ERROR("%s::store_model_features(): kernel is needed to store SV "
                "features.\n", get_name());

    CFeatures* lhs=kernel->get_lhs();
    CFeatures* rhs=kernel->get_rhs();
    if (!lhs)
    {
        SG_ERROR("%s::store_model_features(): kernel lhs is needed to store "
        "SV features.\n", get_name());
    }

    /* this map will be abused as a map */
    CSet<index_t> all_sv;
    for (index_t i=0; i<m_machines->get_num_elements(); ++i)
    {
        CKernelMachine *machine=(CKernelMachine *)get_machine(i);
        for (index_t j=0; j<machine->get_num_support_vectors(); ++j)
            all_sv.add(machine->get_support_vector(j));

        SG_UNREF(machine);
    }

    /* convert map to vector of SV */
    SGVector<index_t> sv_idx(all_sv.get_num_elements());
    for (index_t i=0; i<sv_idx.vlen; ++i)
        sv_idx[i]=*all_sv.get_element_ptr(i);

    CFeatures* sv_features=lhs->copy_subset(sv_idx);

    /* now, features are replaced by concatenated SV features */
    kernel->init(sv_features, rhs);

    /* was SG_REF'ed by copy_subset */
    SG_UNREF(sv_features);

    /* now the old SV indices have to be mapped to the new features */

    /* update SV of all machines */
    for (int32_t i=0; i<m_machines->get_num_elements(); ++i)
    {
        CKernelMachine *machine=(CKernelMachine *)get_machine(i);

        /* for each machine, replace SV by index in sv_idx array */
        for (int32_t j=0; j<machine->get_num_support_vectors(); ++j)
        {
            /* get index of SV in old features */
            index_t current_sv_idx=machine->get_support_vector(j);

            /* the position of this old index in the map is the position of
             * the SV in the new features */
            index_t new_sv_idx=all_sv.index_of(current_sv_idx);

            machine->set_support_vector(j, new_sv_idx);
        }

        SG_UNREF(machine);
    }

    SG_UNREF(lhs);
    SG_UNREF(rhs);
}

CKernelMulticlassMachine::CKernelMulticlassMachine() : CMulticlassMachine(), m_kernel(NULL)
{
    SG_ADD((CSGObject**)&m_kernel,"kernel", "The kernel to be used", MS_AVAILABLE);
}

CKernelMulticlassMachine::CKernelMulticlassMachine(CMulticlassStrategy *strategy, CKernel* kernel, CKernelMachine* machine, CLabels* labs) :
    CMulticlassMachine(strategy,(CMachine*)machine,labs), m_kernel(NULL)
{
    set_kernel(kernel);
    SG_ADD((CSGObject**)&m_kernel,"kernel", "The kernel to be used", MS_AVAILABLE);
}

CKernelMulticlassMachine::~CKernelMulticlassMachine()
{
    SG_UNREF(m_kernel);
}

void CKernelMulticlassMachine::set_kernel(CKernel* k)
{
    ((CKernelMachine*)m_machine)->set_kernel(k);
    SG_REF(k);
    SG_UNREF(m_kernel);
    m_kernel=k;
}

CKernel* CKernelMulticlassMachine::get_kernel()
{
    SG_REF(m_kernel);
    return m_kernel;
}

bool CKernelMulticlassMachine::init_machine_for_train(CFeatures* data)
{
    if (data)
        m_kernel->init(data,data);

    ((CKernelMachine*)m_machine)->set_kernel(m_kernel);

    return true;
}

bool CKernelMulticlassMachine::init_machines_for_apply(CFeatures* data)
{
    if (data)
    {
        /* set data to rhs for this kernel */
        CFeatures* lhs=m_kernel->get_lhs();
        m_kernel->init(lhs, data);
        SG_UNREF(lhs);
    }

    /* set kernel to all sub-machines */
    for (int32_t i=0; i<m_machines->get_num_elements(); i++)
    {
        CKernelMachine *machine=
                (CKernelMachine*)m_machines->get_element(i);
        machine->set_kernel(m_kernel);
        SG_UNREF(machine);
    }

    return true;
}

bool CKernelMulticlassMachine::is_ready()
{
    if (m_kernel && m_kernel->get_num_vec_lhs() && m_kernel->get_num_vec_rhs())
            return true;

    return false;
}

CMachine* CKernelMulticlassMachine::get_machine_from_trained(CMachine* machine)
{
    return new CKernelMachine((CKernelMachine*)machine);
}

int32_t CKernelMulticlassMachine::get_num_rhs_vectors()
{
    return m_kernel->get_num_vec_rhs();
}

void CKernelMulticlassMachine::add_machine_subset(SGVector<index_t> subset)
{
    SG_NOTIMPLEMENTED
}

void CKernelMulticlassMachine::remove_machine_subset()
{
    SG_NOTIMPLEMENTED
}