00001 /* 00002 * This program is free software; you can redistribute it and/or modify 00003 * it under the terms of the GNU General Public License as published by 00004 * the Free Software Foundation; either version 3 of the License, or 00005 * (at your option) any later version. 00006 * 00007 * Written (W) 2012 Chiyuan Zhang 00008 * Copyright (C) 2012 Chiyuan Zhang 00009 */ 00010 00011 #include <shogun/multiclass/MulticlassOneVsRestStrategy.h> 00012 #include <shogun/labels/BinaryLabels.h> 00013 #include <shogun/labels/MulticlassLabels.h> 00014 00015 using namespace shogun; 00016 00017 CMulticlassOneVsRestStrategy::CMulticlassOneVsRestStrategy() 00018 : CMulticlassStrategy() 00019 { 00020 } 00021 00022 SGVector<int32_t> CMulticlassOneVsRestStrategy::train_prepare_next() 00023 { 00024 for (int32_t i=0; i < m_orig_labels->get_num_labels(); ++i) 00025 { 00026 if (((CMulticlassLabels*) m_orig_labels)->get_int_label(i)==m_train_iter) 00027 ((CBinaryLabels*) m_train_labels)->set_label(i, +1.0); 00028 else 00029 ((CBinaryLabels*) m_train_labels)->set_label(i, -1.0); 00030 } 00031 00032 // increase m_train_iter *after* setting labels 00033 CMulticlassStrategy::train_prepare_next(); 00034 00035 return SGVector<int32_t>(); 00036 } 00037 00038 int32_t CMulticlassOneVsRestStrategy::decide_label(SGVector<float64_t> outputs) 00039 { 00040 if (m_rejection_strategy && m_rejection_strategy->reject(outputs)) 00041 return CDenseLabels::REJECTION_LABEL; 00042 00043 return SGVector<float64_t>::arg_max(outputs.vector, 1, outputs.vlen); 00044 } 00045 00046 SGVector<index_t> CMulticlassOneVsRestStrategy::decide_label_multiple_output(SGVector<float64_t> outputs, int32_t n_outputs) 00047 { 00048 float64_t* outputs_ = SG_MALLOC(float64_t, outputs.vlen); 00049 int32_t* indices_ = SG_MALLOC(int32_t, outputs.vlen); 00050 for (int32_t i=0; i<outputs.vlen; i++) 00051 { 00052 outputs_[i] = outputs[i]; 00053 indices_[i] = i; 00054 } 00055 CMath::qsort_backward_index(outputs_,indices_,outputs.vlen); 00056 SGVector<index_t> result(n_outputs); 00057 for (int32_t i=0; i<n_outputs; i++) 00058 result[i] = indices_[i]; 00059 SG_FREE(outputs_); 00060 SG_FREE(indices_); 00061 return result; 00062 } 00063