word2vec源码解析之word2vec.c
最近研究了一下google的开源项目word2vector,http://code.google.com/p/word2vec/。
其实这玩意算是神经网络在文本挖掘的一项成功应用。
//下面是我对word2vec.c的注释 //详细算法可以参考论文,或者看这篇博客 http://www.cnblogs.com/downtjs/p/3784440.html // Copyright 2013 Google Inc. All Rights Reserved. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. #include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h> #include <pthread.h> #define MAX_STRING 100 #define EXP_TABLE_SIZE 1000 #define MAX_EXP 6 #define MAX_SENTENCE_LENGTH 1000 #define MAX_CODE_LENGTH 40 const int vocab_hash_size = 30000000; // Maximum 30 * 0.7 = 21M words in the vocabulary typedef float real; // Precision of float numbers struct vocab_word { long long cn;//词频 int *point;//huffman编码对应内节点的路径 char *word, *code, codelen;//huffman编码 }; char train_file[MAX_STRING], output_file[MAX_STRING]; char save_vocab_file[MAX_STRING], read_vocab_file[MAX_STRING]; struct vocab_word *vocab; int binary = 0, cbow = 0, debug_mode = 2, window = 5, min_count = 5, num_threads = 1, min_reduce = 1; int *vocab_hash; long long vocab_max_size = 1000, vocab_size = 0, layer1_size = 100; long long train_words = 0, word_count_actual = 0, file_size = 0, classes = 0; real alpha = 0.025, starting_alpha, sample = 0; real *syn0, *syn1, *syn1neg, *expTable; clock_t start; int hs = 1, negative = 0; const int table_size = 1e8; int *table; //每个单词的能量分布表,table在负样本抽样中用到 void InitUnigramTable() { int a, i; long long train_words_pow = 0; real d1, power = 0.75; table = (int *)malloc(table_size * sizeof(int)); for (a = 0; a < vocab_size; a++) //遍历词汇表,统计词的能量总值train_words_pow,指数power应该是缩小值的吧。 train_words_pow += pow(vocab[a].cn, power); i = 0; d1 = pow(vocab[i].cn, power) / (real)train_words_pow;//表示已遍历的词的能量值占总能力值的比例 for (a = 0; a < table_size; a++)//遍历table。a表示table的位置,i表示词汇表的位置 { table[a] = i;//单词i占用table的a位置 //table反映的是一个单词能量的分布,一个单词能量越大,所占用的table的位置越多 if (a / (real)table_size > d1) { i++;//移动到下一个词 d1 += pow(vocab[i].cn, power) / (real)train_words_pow; } if (i >= vocab_siInitNetze) i = vocab_size - 1; } } // Reads a single word from a file, assuming space + tab + EOL to be word boundaries //从文件中读取一个词 void ReadWord(char *word, FILE *fin) { int a = 0, ch; while (!feof(fin)) { ch = fgetc(fin); if (ch == 13) continue; if ((ch == ' ') || (ch == '\t') || (ch == '\n')) { if (a > 0) { if (ch == '\n') ungetc(ch, fin); break; } if (ch == '\n') { strcpy(word, (char *)"</s>"); return; } else continue; } word[a] = ch; a++; if (a >= MAX_STRING - 1) a--; // Truncate too long words } word[a] = 0; } // Returns hash value of a word返回一个词的hash值,一个词跟hash值一一对应(可能冲突) int GetWordHash(char *word) { unsigned long long a, hash = 0; for (a = 0; a < strlen(word); a++) hash = hash * 257 + word[a];//采取257进制 hash = hash % vocab_hash_size; return hash; } // Returns position of a word in the vocabulary; if the word is not found, returns -1 // 返回一个词在词汇表中的位置,如果不存在则返回-1 int SearchVocab(char *word) { unsigned int hash = GetWordHash(word); while (1) { if (vocab_hash[hash] == -1) return -1; if (!strcmp(word, vocab[vocab_hash[hash]].word)) return vocab_hash[hash]; hash = (hash + 1) % vocab_hash_size; } return -1; } // Reads a word and returns its index in the vocabulary // 从文件流中读取一个词,并返回这个词在词汇表中的位置 int ReadWordIndex(FILE *fin) { char word[MAX_STRING]; ReadWord(word, fin); if (feof(fin)) return -1; return SearchVocab(word); } // Adds a word to the vocabulary 将一个词添加到一个词汇中 int AddWordToVocab(char *word) { unsigned int hash, length = strlen(word) + 1; if (length > MAX_STRING) length = MAX_STRING; vocab[vocab_size].word = (char *)calloc(length, sizeof(char)); strcpy(vocab[vocab_size].word, word); vocab[vocab_size].cn = 0; vocab_size++; // Reallocate memory if needed if (vocab_size + 2 >= vocab_max_size) { vocab_max_size += 1000; vocab = (struct vocab_word *)realloc(vocab, vocab_max_size * sizeof(struct vocab_word)); } hash = GetWordHash(word); while (vocab_hash[hash] != -1)//如果hash值冲突了 hash = (hash + 1) % vocab_hash_size;//使用开放地址法解决冲突 vocab_hash[hash] = vocab_size - 1;//由词的hash值找到她所在词汇表的排序位置 return vocab_size - 1; } // Used later for sorting by word counts int VocabCompare(const void *a, const void *b) { return ((struct vocab_word *)b)->cn - ((struct vocab_word *)a)->cn; } // Sorts the vocabulary by frequency using word counts // 根据词频排序 void SortVocab() { int a, size; unsigned int hash; // Sort the vocabulary and keep </s> at the first position qsort(&vocab[1], vocab_size - 1, sizeof(struct vocab_word), VocabCompare); for (a = 0; a < vocab_hash_size; a++) vocab_hash[a] = -1; size = vocab_size; train_words = 0; for (a = 0; a < size; a++) { // Words occuring less than min_count times will be discarded from the vocab //出现太少的词直接丢弃 if (vocab[a].cn < min_count) { vocab_size--; free(vocab[vocab_size].word); } else { // Hash will be re-computed, as after the sorting it is not actual // 重新计算hash查找。vocab_hash是由hash值找到该词所在位置 hash=GetWordHash(vocab[a].word); while (vocab_hash[hash] != -1) hash = (hash + 1) % vocab_hash_size; vocab_hash[hash] = a; train_words += vocab[a].cn; } } vocab = (struct vocab_word *)realloc(vocab, (vocab_size + 1) * sizeof(struct vocab_word)); // Allocate memory for the binary tree construction for (a = 0; a < vocab_size; a++) { vocab[a].code = (char *)calloc(MAX_CODE_LENGTH, sizeof(char)); vocab[a].point = (int *)calloc(MAX_CODE_LENGTH, sizeof(int)); } } // Reduces the vocabulary by removing infrequent tokens // 再次移除词频过小的词,缩减词汇表 void ReduceVocab() { int a, b = 0; unsigned int hash; for (a = 0; a < vocab_size; a++)//我草,这很容易看错啊 if (vocab[a].cn > min_reduce) { vocab[b].cn = vocab[a].cn; vocab[b].word = vocab[a].word; b++; } else free(vocab[a].word); vocab_size = b; for (a = 0; a < vocab_hash_size; a++) vocab_hash[a] = -1; for (a = 0; a < vocab_size; a++) { // Hash will be re-computed, as it is not actual hash = GetWordHash(vocab[a].word); while (vocab_hash[hash] != -1) hash = (hash + 1) % vocab_hash_size; vocab_hash[hash] = a; } fflush(stdout); min_reduce++; } // Create binary Huffman tree using the word counts根据词频创建huffman树 // Frequent words will have short uniqe binary codes词频越大的单词有越短的huffman编码 void CreateBinaryTree() { long long a, b, i, min1i, min2i, pos1, pos2, point[MAX_CODE_LENGTH]; char code[MAX_CODE_LENGTH]; long long *count = (long long *)calloc(vocab_size * 2 + 1, sizeof(long long)); long long *binary = (long long *)calloc(vocab_size * 2 + 1, sizeof(long long)); long long *parent_node = (long long *)calloc(vocab_size * 2 + 1, sizeof(long long)); for (a = 0; a < vocab_size; a++) count[a] = vocab[a].cn; for (a = vocab_size; a < vocab_size * 2; a++) count[a] = 1e15; pos1 = vocab_size - 1; pos2 = vocab_size; // Following algorithm constructs the Huffman tree by adding one node at a time for (a = 0; a < vocab_size - 1; a++) { // First, find two smallest nodes 'min1, min2' 找出目前权值最小的两个节点 if (pos1 >= 0)//第一个权值最小的节点 { if (count[pos1] < count[pos2]) { min1i = pos1; pos1--; } else { min1i = pos2; pos2++; } } else { min1i = pos2; pos2++; } if (pos1 >= 0)//第二个权值最小的节点 { if (count[pos1] < count[pos2]) { min2i = pos1; pos1--; } else { min2i = pos2; pos2++; } } else { min2i = pos2; pos2++; } count[vocab_size + a] = count[min1i] + count[min2i]; parent_node[min1i] = vocab_size + a; parent_node[min2i] = vocab_size + a; binary[min2i] = 1;//节点编码为1,之前默认是0。 } // Now assign binary code to each vocabulary word for (a = 0; a < vocab_size; a++) { b = a; i = 0; while (1) { code[i] = binary[b]; point[i] = b; i++; b = parent_node[b]; if (b == vocab_size * 2 - 2) break; } vocab[a].codelen = i; vocab[a].point[0] = vocab_size - 2; for (b = 0; b < i; b++) { vocab[a].code[i - b - 1] = code[b]; vocab[a].point[i - b] = point[b] - vocab_size; } } free(count); free(binary); free(parent_node); } //从分词文件中统计每个单词的词频 void LearnVocabFromTrainFile() { char word[MAX_STRING]; FILE *fin; long long a, i; for (a = 0; a < vocab_hash_size; a++) vocab_hash[a] = -1; fin = fopen(train_file, "rb"); if (fin == NULL) { printf("ERROR: training data file not found!\n"); exit(1); } vocab_size = 0; AddWordToVocab((char *)"</s>"); while (1) { ReadWord(word, fin); if (feof(fin)) break; train_words++; if ((debug_mode > 1) && (train_words % 100000 == 0)) { printf("%lldK%c", train_words / 1000, 13); fflush(stdout); } i = SearchVocab(word);//返回该词在词汇表中的位置 if (i == -1)//该词之前不存在 { a = AddWordToVocab(word);//把该词添加到词汇表中 vocab[a].cn = 1; } else vocab[i].cn++;//更新词频 if (vocab_size > vocab_hash_size * 0.7)//如果词汇表太庞大,就缩减 ReduceVocab(); } SortVocab();//根据词频排序词汇表 if (debug_mode > 0) { printf("Vocab size: %lld\n", vocab_size); printf("Words in train file: %lld\n", train_words); } file_size = ftell(fin); fclose(fin); } void SaveVocab() { long long i; FILE *fo = fopen(save_vocab_file, "wb"); for (i = 0; i < vocab_size; i++) fprintf(fo, "%s %lld\n", vocab[i].word, vocab[i].cn); fclose(fo); } //从文件读取词汇,该文件已经统计好了每个词汇的词频 void ReadVocab() { long long a, i = 0; char c; char word[MAX_STRING]; FILE *fin = fopen(read_vocab_file, "rb");//打开词汇文件 if (fin == NULL) { printf("Vocabulary file not found\n"); exit(1); } for (a = 0; a < vocab_hash_size; a++) vocab_hash[a] = -1; vocab_size = 0; while (1) { ReadWord(word, fin);//从fin进入一个词到word中 if (feof(fin)) break; a = AddWordToVocab(word);//把该词添加到词汇中,并返回该词的位置 fscanf(fin, "%lld%c", &vocab[a].cn, &c);//读取词频?c是干啥的吗,读取空格吗 i++; } SortVocab();//根据词频排序 if (debug_mode > 0) { printf("Vocab size: %lld\n", vocab_size); printf("Words in train file: %lld\n", train_words); } //读取训练数据 fin = fopen(train_file, "rb"); if (fin == NULL) { printf("ERROR: training data file not found!\n"); exit(1); } fseek(fin, 0, SEEK_END); file_size = ftell(fin); fclose(fin); } void InitNet() { long long a, b; a = posix_memalign((void **)&syn0, 128, (long long)vocab_size * layer1_size * sizeof(real)); //先知道这个也是申请动态数组,对齐还有128这个参数以后再了解 if (syn0 == NULL) { printf("Memory allocation failed\n"); exit(1); } if (hs)//采用softmax { a = posix_memalign((void **)&syn1, 128, (long long)vocab_size * layer1_size * sizeof(real)); if (syn1 == NULL) { printf("Memory allocation failed\n"); exit(1); } for (b = 0; b < layer1_size; b++) for (a = 0; a < vocab_size; a++) syn1[a * layer1_size + b] = 0; } if (negative>0)//还有负样本 { a = posix_memalign((void **)&syn1neg, 128, (long long)vocab_size * layer1_size * sizeof(real)); if (syn1neg == NULL) { printf("Memory allocation failed\n"); exit(1); } for (b = 0; b < layer1_size; b++) for (a = 0; a < vocab_size; a++) syn1neg[a * layer1_size + b] = 0; } for (b = 0; b < layer1_size; b++) for (a = 0; a < vocab_size; a++) syn0[a * layer1_size + b] = (rand() / (real)RAND_MAX - 0.5) / layer1_size; CreateBinaryTree();//建立huffman树,对每个单词进行编码 } //这个线程函数执行之前,已经做好了一些工作:根据词频排序的词汇表,每个单词的huffman编码 void *TrainModelThread(void *id) { long long a, b, d, word, last_word, sentence_length = 0, sentence_position = 0; long long word_count = 0, last_word_count = 0, sen[MAX_SENTENCE_LENGTH + 1]; long long l1, l2, c, target, label; unsigned long long next_random = (long long)id; real f, g; clock_t now; real *neu1 = (real *)calloc(layer1_size, sizeof(real)); real *neu1e = (real *)calloc(layer1_size, sizeof(real)); FILE *fi = fopen(train_file, "rb"); //每个线程对应一段文本。根据线程id找到自己负责的文本的初始位置 fseek(fi, file_size / (long long)num_threads * (long long)id, SEEK_SET); while (1) { if (word_count - last_word_count > 10000) { word_count_actual += word_count - last_word_count; last_word_count = word_count; if ((debug_mode > 1)) { now=clock(); printf("%cAlpha: %f Progress: %.2f%% Words/thread/sec: %.2fk ", 13, alpha, word_count_actual / (real)(train_words + 1) * 100, word_count_actual / ((real)(now - start + 1) / (real)CLOCKS_PER_SEC * 1000)); fflush(stdout); } alpha = starting_alpha * (1 - word_count_actual / (real)(train_words + 1)); if (alpha < starting_alpha * 0.0001) alpha = starting_alpha * 0.0001; } if (sentence_length == 0) { while (1) { word = ReadWordIndex(fi);//从文件流中读取一个词,并返回这个词在词汇表中的位置 if (feof(fi)) break; if (word == -1) continue; word_count++; if (word == 0) break; // The subsampling randomly discards frequent words while keeping the ranking same if (sample > 0)//对高频词进行下采样,不过要保持排序不变。 { real ran = (sqrt(vocab[word].cn / (sample * train_words)) + 1) * (sample * train_words) / vocab[word].cn; next_random = next_random * (unsigned long long)25214903917 + 11; if (ran < (next_random & 0xFFFF) / (real)65536) continue; } sen[sentence_length] = word; sentence_length++; //1000个单词视作一个句子? if (sentence_length >= MAX_SENTENCE_LENGTH) break; } sentence_position = 0; } if (feof(fi)) break; if (word_count > train_words / num_threads) break;//如果当前线程已处理的单词超过了 阈值,则退出。 word = sen[sentence_position]; if (word == -1) continue; for (c = 0; c < layer1_size; c++) neu1[c] = 0; for (c = 0; c < layer1_size; c++) neu1e[c] = 0; next_random = next_random * (unsigned long long)25214903917 + 11; b = next_random % window; if (cbow) { //train the cbow architecture // in -> hidden for (a = b; a < window * 2 + 1 - b; a++) if (a != window)//扫描目标单词的左右几个单词 { c = sentence_position - window + a; if (c < 0) continue; if (c >= sentence_length) continue; last_word = sen[c]; if (last_word == -1) continue; for (c = 0; c < layer1_size; c++)//layer1_size词向量的维度,默认值是100 neu1[c] += syn0[c + last_word * layer1_size];//传说中的向量和? } if (hs) for (d = 0; d < vocab[word].codelen; d++)//开始遍历huffman树,每次一个节点 { f = 0; l2 = vocab[word].point[d] * layer1_size;//point应该记录的是huffman的路径。找到当前节点,并算出偏移 // Propagate hidden -> output for (c = 0; c < layer1_size; c++) f += neu1[c] * syn1[c + l2];//计算内积 if (f <= -MAX_EXP) continue;//内积不在范围内直接丢弃 else if (f >= MAX_EXP) continue; else f = expTable[(int)((f + MAX_EXP) * (EXP_TABLE_SIZE / MAX_EXP / 2))];//内积之后sigmoid函数 // 'g' is the gradient multiplied by the learning rate g = (1 - vocab[word].code[d] - f) * alpha;//偏导数的一部分 //layer1_size是向量的维度 // Propagate errors output -> hidden 反向传播误差,从huffman树传到隐藏层。下面就是把当前内节点的误差传播给隐藏层,syn1[c + l2]是偏导数的一部分。 for (c = 0; c < layer1_size; c++) neu1e[c] += g * syn1[c + l2]; // Learn weights hidden -> output 更新当前内节点的向量,后面的neu1[c]其实是偏导数的一部分 for (c = 0; c < layer1_size; c++) syn1[c + l2] += g * neu1[c]; } // NEGATIVE SAMPLING if (negative > 0) for (d = 0; d < negative + 1; d++) { if (d == 0) { target = word;//目标单词 label = 1;//正样本 } else { next_random = next_random * (unsigned long long)25214903917 + 11; target = table[(next_random >> 16) % table_size]; if (target == 0) target = next_random % (vocab_size - 1) + 1; if (target == word) continue; label = 0;//负样本 } l2 = target * layer1_size; f = 0; for (c = 0; c < layer1_size; c++) f += neu1[c] * syn1neg[c + l2];//内积 if (f > MAX_EXP) g = (label - 1) * alpha; else if (f < -MAX_EXP) g = (label - 0) * alpha; else g = (label - expTable[(int)((f + MAX_EXP) * (EXP_TABLE_SIZE / MAX_EXP / 2))]) * alpha; for (c = 0; c < layer1_size; c++) neu1e[c] += g * syn1neg[c + l2];//隐藏层的误差 for (c = 0; c < layer1_size; c++) syn1neg[c + l2] += g * neu1[c];//更新负样本向量 } // hidden -> in for (a = b; a < window * 2 + 1 - b; a++) if (a != window)//cbow模型 更新的不是中间词语的向量,而是周围几个词语的向量。 { c = sentence_position - window + a; if (c < 0) continue; if (c >= sentence_length) continue; last_word = sen[c]; if (last_word == -1) continue; for (c = 0; c < layer1_size; c++) syn0[c + last_word * layer1_size] += neu1e[c];//更新词向量 } } else { //train skip-gram for (a = b; a < window * 2 + 1 - b; a++) if (a != window)//扫描周围几个词语 { c = sentence_position - window + a; if (c < 0) continue; if (c >= sentence_length) continue; last_word = sen[c]; if (last_word == -1) continue; l1 = last_word * layer1_size; for (c = 0; c < layer1_size; c++) neu1e[c] = 0; // HIERARCHICAL SOFTMAX if (hs) for (d = 0; d < vocab[word].codelen; d++)//遍历叶子节点 { f = 0; l2 = vocab[word].point[d] * layer1_size;//point记录的是huffman的路径 // Propagate hidden -> output 感觉源代码这个英语注释有点误导人,这里的隐藏层就是输入层,就是词向量。 for (c = 0; c < layer1_size; c++) f += syn0[c + l1] * syn1[c + l2];//计算两个词向量的内积 if (f <= -MAX_EXP) continue; else if (f >= MAX_EXP) continue; else f = expTable[(int)((f + MAX_EXP) * (EXP_TABLE_SIZE / MAX_EXP / 2))]; // 'g' is the gradient multiplied by the learning rate g = (1 - vocab[word].code[d] - f) * alpha;//偏导数的一部分 // Propagate errors output -> hidden for (c = 0; c < layer1_size; c++) neu1e[c] += g * syn1[c + l2];//隐藏层的误差 // Learn weights hidden -> output for (c = 0; c < layer1_size; c++) syn1[c + l2] += g * syn0[c + l1];//更新叶子节点向量 } // NEGATIVE SAMPLING if (negative > 0)//这个同cobow差不多 for (d = 0; d < negative + 1; d++) { if (d == 0) { target = word; label = 1; } else { next_random = next_random * (unsigned long long)25214903917 + 11; target = table[(next_random >> 16) % table_size]; if (target == 0) target = next_random % (vocab_size - 1) + 1; if (target == word) continue; label = 0; } l2 = target * layer1_size; f = 0; for (c = 0; c < layer1_size; c++) f += syn0[c + l1] * syn1neg[c + l2]; if (f > MAX_EXP) g = (label - 1) * alpha; else if (f < -MAX_EXP) g = (label - 0) * alpha; else g = (label - expTable[(int)((f + MAX_EXP) * (EXP_TABLE_SIZE / MAX_EXP / 2))]) * alpha; for (c = 0; c < layer1_size; c++) neu1e[c] += g * syn1neg[c + l2]; for (c = 0; c < layer1_size; c++) syn1neg[c + l2] += g * syn0[c + l1]; } // Learn weights input -> hidden for (c = 0; c < layer1_size; c++) syn0[c + l1] += neu1e[c];//更新周围几个词语的向量 } } sentence_position++; if (sentence_position >= sentence_length) { sentence_length = 0; continue; } } fclose(fi); free(neu1); free(neu1e); pthread_exit(NULL); } void TrainModel() { long a, b, c, d; FILE *fo; pthread_t *pt = (pthread_t *)malloc(num_threads * sizeof(pthread_t)); printf("Starting training using file %s\n", train_file); starting_alpha = alpha; if (read_vocab_file[0] != 0) ReadVocab();//从文件读入词汇 else LearnVocabFromTrainFile();//从训练文件学习词汇 if (save_vocab_file[0] != 0) SaveVocab();//保存词汇 if (output_file[0] == 0) return; InitNet(); if (negative > 0) InitUnigramTable(); start = clock(); for (a = 0; a < num_threads; a++) pthread_create(&pt[a], NULL, TrainModelThread, (void *)a); for (a = 0; a < num_threads; a++) pthread_join(pt[a], NULL); fo = fopen(output_file, "wb"); if (classes == 0) //不需要聚类,只需要输出词向量 { // Save the word vectors fprintf(fo, "%lld %lld\n", vocab_size, layer1_size); for (a = 0; a < vocab_size; a++) { fprintf(fo, "%s ", vocab[a].word); if (binary) for (b = 0; b < layer1_size; b++) fwrite(&syn0[a * layer1_size + b], sizeof(real), 1, fo); else for (b = 0; b < layer1_size; b++) fprintf(fo, "%lf ", syn0[a * layer1_size + b]); fprintf(fo, "\n"); } } else //使用k-means进行聚类 { // Run K-means on the word vectors int clcn = classes, iter = 10, closeid; int *centcn = (int *)malloc(classes * sizeof(int));//该类别的数量 int *cl = (int *)calloc(vocab_size, sizeof(int));//词到类别的映射 real closev, x; real *cent = (real *)calloc(classes * layer1_size, sizeof(real));//质心数组 for (a = 0; a < vocab_size; a++) cl[a] = a % clcn;//任意分类? for (a = 0; a < iter; a++) { for (b = 0; b < clcn * layer1_size; b++) cent[b] = 0;//质心清零 for (b = 0; b < clcn; b++) centcn[b] = 1; for (c = 0; c < vocab_size; c++) { for (d = 0; d < layer1_size; d++) cent[layer1_size * cl[c] + d] += syn0[c * layer1_size + d];//求和放到质心数组中 centcn[cl[c]]++;//类别数量加1 } for (b = 0; b < clcn; b++)//遍历所有类别 { closev = 0; for (c = 0; c < layer1_size; c++) { cent[layer1_size * b + c] /= centcn[b];//均值,就是求新的质心 closev += cent[layer1_size * b + c] * cent[layer1_size * b + c]; } closev = sqrt(closev); for (c = 0; c < layer1_size; c++) cent[layer1_size * b + c] /= closev;//对质心进行归一化? } for (c = 0; c < vocab_size; c++)//对所有词语重新分类 { closev = -10; closeid = 0; for (d = 0; d < clcn; d++) { x = 0; for (b = 0; b < layer1_size; b++) x += cent[layer1_size * d + b] * syn0[c * layer1_size + b];//内积 if (x > closev) { closev = x; closeid = d; } } cl[c] = closeid; } } // Save the K-means classes for (a = 0; a < vocab_size; a++) fprintf(fo, "%s %d\n", vocab[a].word, cl[a]); free(centcn); free(cent); free(cl); } fclose(fo); } int ArgPos(char *str, int argc, char **argv) { int a; for (a = 1; a < argc; a++) if (!strcmp(str, argv[a])) { if (a == argc - 1) { printf("Argument missing for %s\n", str); exit(1); } return a; } return -1; } int main(int argc, char **argv) { int i; if (argc == 1) { printf("WORD VECTOR estimation toolkit v 0.1b\n\n"); printf("Options:\n"); printf("Parameters for training:\n"); //输入文件:已分词的语料 printf("\t-train <file>\n"); printf("\t\tUse text data from <file> to train the model\n"); //输出文件:词向量或者词聚类 printf("\t-output <file>\n"); printf("\t\tUse <file> to save the resulting word vectors / word clusters\n"); //词向量的维度,默认值是100 printf("\t-size <int>\n"); printf("\t\tSet size of word vectors; default is 100\n"); //窗口大小,默认是5 printf("\t-window <int>\n"); printf("\t\tSet max skip length between words; default is 5\n"); //设定词出现频率的阈值,对于常出现的词会被随机下采样 printf("\t-sample <float>\n"); printf("\t\tSet threshold for occurrence of words. Those that appear with higher frequency"); printf(" in the training data will be randomly down-sampled; default is 0 (off), useful value is 1e-5\n"); //是否采用softmax体系 printf("\t-hs <int>\n"); printf("\t\tUse Hierarchical Softmax; default is 1 (0 = not used)\n"); //负样本的数量,默认是0,通常使用5-10。0表示不使用。 printf("\t-negative <int>\n"); printf("\t\tNumber of negative examples; default is 0, common values are 5 - 10 (0 = not used)\n"); //开启的线程数量 printf("\t-threads <int>\n"); printf("\t\tUse <int> threads (default 1)\n"); //最小阈值。对于出现次数少于该值的词,会被抛弃掉。 printf("\t-min-count <int>\n"); printf("\t\tThis will discard words that appear less than <int> times; default is 5\n"); //学习速率初始值,默认是0.025 printf("\t-alpha <float>\n"); printf("\t\tSet the starting learning rate; default is 0.025\n"); //输出词类别,而不是词向量 printf("\t-classes <int>\n"); printf("\t\tOutput word classes rather than word vectors; default number of classes is 0 (vectors are written)\n"); //debug模式,默认是2,表示在训练过程中会输出更多信息 printf("\t-debug <int>\n"); printf("\t\tSet the debug mode (default = 2 = more info during training)\n"); //是否用binary模式保存数据,默认是0,表示否。 printf("\t-binary <int>\n"); printf("\t\tSave the resulting vectors in binary moded; default is 0 (off)\n"); //保存词汇到这个文件 printf("\t-save-vocab <file>\n"); printf("\t\tThe vocabulary will be saved to <file>\n"); //词汇从该文件读取,而不是由训练数据重组 printf("\t-read-vocab <file>\n"); printf("\t\tThe vocabulary will be read from <file>, not constructed from the training data\n"); //是否采用continuous bag of words算法。默认是0,表示采用另一个叫skip-gram的算法。 printf("\t-cbow <int>\n"); printf("\t\tUse the continuous bag of words model; default is 0 (skip-gram model)\n"); //工具使用样例 printf("\nExamples:\n"); printf("./word2vec -train data.txt -output vec.txt -debug 2 -size 200 -window 5 -sample 1e-4 -negative 5 -hs 0 -binary 0 -cbow 1\n\n"); return 0; } output_file[0] = 0; save_vocab_file[0] = 0; read_vocab_file[0] = 0; if ((i = ArgPos((char *)"-size", argc, argv)) > 0) layer1_size = atoi(argv[i + 1]); if ((i = ArgPos((char *)"-train", argc, argv)) > 0) strcpy(train_file, argv[i + 1]); if ((i = ArgPos((char *)"-save-vocab", argc, argv)) > 0) strcpy(save_vocab_file, argv[i + 1]); if ((i = ArgPos((char *)"-read-vocab", argc, argv)) > 0) strcpy(read_vocab_file, argv[i + 1]); if ((i = ArgPos((char *)"-debug", argc, argv)) > 0) debug_mode = atoi(argv[i + 1]); if ((i = ArgPos((char *)"-binary", argc, argv)) > 0) binary = atoi(argv[i + 1]); if ((i = ArgPos((char *)"-cbow", argc, argv)) > 0) cbow = atoi(argv[i + 1]); if ((i = ArgPos((char *)"-alpha", argc, argv)) > 0) alpha = atof(argv[i + 1]); if ((i = ArgPos((char *)"-output", argc, argv)) > 0) strcpy(output_file, argv[i + 1]); if ((i = ArgPos((char *)"-window", argc, argv)) > 0) window = atoi(argv[i + 1]); if ((i = ArgPos((char *)"-sample", argc, argv)) > 0) sample = atof(argv[i + 1]); if ((i = ArgPos((char *)"-hs", argc, argv)) > 0) hs = atoi(argv[i + 1]); if ((i = ArgPos((char *)"-negative", argc, argv)) > 0) negative = atoi(argv[i + 1]); if ((i = ArgPos((char *)"-threads", argc, argv)) > 0) num_threads = atoi(argv[i + 1]); if ((i = ArgPos((char *)"-min-count", argc, argv)) > 0) min_count = atoi(argv[i + 1]); if ((i = ArgPos((char *)"-classes", argc, argv)) > 0) classes = atoi(argv[i + 1]); vocab = (struct vocab_word *)calloc(vocab_max_size, sizeof(struct vocab_word)); vocab_hash = (int *)calloc(vocab_hash_size, sizeof(int)); expTable = (real *)malloc((EXP_TABLE_SIZE + 1) * sizeof(real)); for (i = 0; i < EXP_TABLE_SIZE; i++) { //expTable[i] = exp((i -500)/ 500 * 6) 即 e^-6 ~ e^6 expTable[i] = exp((i / (real)EXP_TABLE_SIZE * 2 - 1) * MAX_EXP); // Precompute the exp() table //expTable[i] = 1/(1+e^6) ~ 1/(1+e^-6)即 0.01 ~ 1 的样子 expTable[i] = expTable[i] / (expTable[i] + 1); // Precompute f(x) = x / (x + 1) } TrainModel(); return 0; }
本文作者:linger
本文链接:http://blog.csdn.net/lingerlanlan/article/details/38232755