PPIExtend Online Document 
Contents
Introduction
Installation
Input data
Running PPIExtend
Output
 Introduction 
PPIExtend is a tool for finding quasi-bicliques in PPI Networks.
PPIExtend is now available for Linux. 
PPIExtend is implemented in Java. 
To run PPIExtend, Sun's Java Running 
Environment (JRE) 6.0 is required. If JRE is not installed, please go to
http://java.sun.com/ 
to download and install the JRE.
 
 Installation 
 
1. Download the file PPIE_1.0.0.tar.gz.   
Click here.
 
2. Extract the downloaded file.  
tar xvfz PPIE_1.0.0.tar.gz   
cd PPIE_1.0.0   
	
3. Make sure that execute permission is set on the setup shell script  
 chmod +x setup.sh   
 
4. Run the setup shell script  
 ./setup.sh  
 
5. Move the shell script PPIExtend to a /bin directory.  
For example 
 mv  PPIExtend ~/bin  
 Input data 
In the input file, each line contains a pair of interacting proteins. The two protein names are seperated by a space. 
For example, see file input_example.txt.
 Running PPIExtend 
Run PPIExtend with five arguments:
(1) input file name (2) delta (3) tau (4) alpha (5) result file name.
Input file name and result file name are self explanatory.
The three parameters delta, tau and alpha are discussed in the paper.
Delta is a real number. Tau and alpha are two positive integers.  
Suppose the input file name is "input_example.txt", the result file name is "result_example.txt", delta = 0.1,
and tau = 5 and alpha = 5. We use 
 PPIExtend input_example.txt 0.1 5 5 result_example.txt  
 Output 
In the result file, each quasi-biclique is described 
using three lines. The first line contains the serial number, the numbers of vertices in two vertex sets.
The second line is the list of the vertices in the the first vertex set and the third line is the list of 
vertices of the second vertex set.
For example, see result_example.txt.