Information retriveal

This repository contains codes that are required by course CS6200 of Summer 2015 in Northeastern Univiersity. Generally there are 7 parts of the homework in the repository:

1. Retrieval Model: (1) native model (2) probalitity model (3) language model
2. Index
3. Crawl (muti-processing)
4. Evaluation
5. Link Analysis Algorithms
6. Machine Learning
7. Spam filter with ML

Over all, the Index and Crawl part are the most valuable part of this repository. They are both effencicy and bug free.