From d91e11a3e0e3215db7b87eb902dc7e7f9974823f Mon Sep 17 00:00:00 2001
From: Peng Wu <alexepico@gmail.com>
Date: Wed, 4 May 2011 13:45:16 +0800
Subject: wrote prune k mixture model

---
 utils/training/prune_k_mixture_model.cpp | 105 +++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)

(limited to 'utils')

diff --git a/utils/training/prune_k_mixture_model.cpp b/utils/training/prune_k_mixture_model.cpp
index f6f0bcc..7a724a9 100644
--- a/utils/training/prune_k_mixture_model.cpp
+++ b/utils/training/prune_k_mixture_model.cpp
@@ -1,9 +1,114 @@
+/* 
+ *  libpinyin
+ *  Library to deal with pinyin.
+ *  
+ *  Copyright (C) 2011 Peng Wu <alexepico@gmail.com>
+ *  
+ *  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 2 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *  GNU General Public License for more details.
+ *  
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+
+
+#include <errno.h>
+#include <locale.h>
 #include "pinyin.h"
 #include "k_mixture_model.h"
 
 static guint32 g_prune_k = 3;
 static parameter_t g_prune_poss = 0.99;
 
+void print_help(){
+    printf("prune_k_mixture_model <FILENAME>\n");
+}
+
+bool prune_k_mixture_model(KMixtureModelMagicHeader * magic_header,
+                           KMixtureModelSingleGram * & bigram){
+    bool success;
+
+    FlexibleBigramPhraseArray array = g_array_new(FALSE, FALSE, sizeof(KMixtureModelArrayItemWithToken));
+    bigram->retrieve_all(array);
+    for ( size_t i = 0; i < array->len; ++i) {
+        KMixtureModelArrayItemWithToken * item = &g_array_index(array, KMixtureModelArrayItemWithToken, i);
+        phrase_token_t token = item->m_token;
+        parameter_t remained_poss = 1;
+        for ( size_t k = 0; k < g_prune_k; ++k){
+            remained_poss -= compute_Pr_G_3_with_count
+                (k, magic_header->m_N, item->m_item.m_WC,
+                 magic_header->m_N - item->m_item.m_N_n_0,
+                 item->m_item.m_n_1);
+        }
+
+        assert(remained_poss >= 0);
+        if ( remained_poss < g_prune_poss ) {
+            /* prune this word or phrase. */
+            KMixtureModelArrayItem removed_item;
+            bigram->remove_array_item(token, removed_item);
+            assert( memcmp(&removed_item, &(item->m_item),
+                           sizeof(KMixtureModelArrayItem)) == 0 );
+            KMixtureModelArrayHeader header;
+            bigram->get_array_header(header);
+            guint32 removed_count = removed_item.m_WC;
+            header.m_WC -= removed_count;
+            bigram->set_array_header(header);
+            magic_header->m_WC -= removed_count;
+        }
+    }
+
+    KMixtureModelArrayHeader header;
+    bigram->get_array_header(header);
+
+    if ( 0 == header.m_WC ){
+        delete bigram;
+        bigram = NULL;
+    }
+
+    return true;
+}
+
 int main(int argc, char * argv[]){
+    const char * bigram_filename = NULL;
+
+    setlocale(LC_ALL, "");
+    if ( 2 != argc ){
+        print_help();
+        exit(EINVAL);
+    } else {
+        bigram_filename = argv[1];
+    }
+
+    /* TODO: magic header signature check here. */
+    KMixtureModelBigram bigram(K_MIXTURE_MODEL_MAGIC_NUMBER);
+    bigram.attach(bigram_filename);
+
+    KMixtureModelMagicHeader magic_header;
+    bigram.get_magic_header(magic_header);
+    GArray * items = g_array_new(FALSE, FALSE, sizeof(phrase_token_t));
+    bigram.get_all_items(items);
+
+    for ( size_t i; i < items->len; ++i ){
+        phrase_token_t * token = &g_array_index(items, phrase_token_t, i);
+        KMixtureModelSingleGram * single_gram = NULL;
+        bigram.load(*token, single_gram);
+
+        prune_k_mixture_model(&magic_header, single_gram);
+
+        if ( NULL == single_gram )
+            bigram.remove(*token);
+        else bigram.store(*token, single_gram);
+    }
+
+    bigram.set_magic_header(magic_header);
     return 0;
 }
-- 
cgit