// This code is based on Mikolov's word2vec, version r42 https://code.google.com/p/word2vec/source/detail?r=42.
// It has all the functionalities of word2vec with the following added features:
//   (a) Train bilingual embeddings as described in the paper "Bilingual Word Representations with Monolingual Quality in Mind".
//   (b) When training bilingual embeddings for English and German, it automatically produces the cross-lingual document classification results.
//   (c) For monolingual embeddings, the code outputs word similarity results for English, German and word analogy results for English.
//   (d) Save output vectors besides input vectors.
//   (e) Automatically save vocab file and load vocab (if there's one exists).
//   (f) The code has been extensively refactored to make it easier to understand and more comments have been added.
//
// Thang Luong @ 2014, 2015, <lmthang@stanford.edu>
//   with many contributions from Hieu Pham <hyhieu@stanford.edu>

Files & Directories:
(a) demo-bi-*: test various bilingual models.
(b) demo-mono-*: test monolingual models.
(c) wordsim / analogy: code to evaluate trained embeddings on the word similarity and analogy tasks.
(e) run_mono.sh: train mono models.
(f) run_bi.sh: train bilingual embedding models (Note: in this script, we hard-coded the source language to be "de" and the source language to be "en".)
(g) cldc/: cross-lingual document classification (CLDC) task. 
  To be able to obtain the CLDC results during training of the bilingual embeddings, you need the following:
  (i) put under cldc/, the following two directories: src/ for the perceptron code and data/ for the task. These two directories can be obtained from the authors of this paper "Inducing crosslingual distributed rep- resentations of words".
  (ii) go into cldc/, and run ant

Notes:
If you don't have Matlab, modify demo-*.sh to set -eval 0 (instead of -eval 1).

Sample commands:
* Bi model: run_bi.sh remake outputDir trainPrefix dim alignOpt numIters numThreads neg [isCbow alpha sample tgt_sample bi_weight otherOpts]
./run_bi.sh 1 outputDir data/data.10k 50 1 5 4 10
* Mono model: run_mono.sh remake outputDir trainFile lang dim numIters numThreads neg [otherOpts]
./run_mono.sh 1 outputDir data/data.10k.en en 50 5 2 5

-------- Mikolov's README -------

Tools for computing distributed representtion of words
------------------------------------------------------

We provide an implementation of the Continuous Bag-of-Words (CBOW) and the Skip-gram model (SG), as well as several demo scripts.

Given a text corpus, the word2vec tool learns a vector for every word in the vocabulary using the Continuous
Bag-of-Words or the Skip-Gram neural network architectures. The user should to specify the following:
 - desired vector dimensionality
 - the size of the context window for either the Skip-Gram or the Continuous Bag-of-Words model
 - training algorithm: hierarchical softmax and / or negative sampling
 - threshold for downsampling the frequent words 
 - number of threads to use
 - the format of the output word vector file (text or binary)

Usually, the other hyper-parameters such as the learning rate do not need to be tuned for different training sets. 

The script demo-word.sh downloads a small (100MB) text corpus from the web, and trains a small word vector model. After the training
is finished, the user can interactively explore the similarity of the words.

More information about the scripts is provided at https://code.google.com/p/word2vec/