This is a repository created by Andrej Jurco, Paolo Sylos Labini and Flavio Vella. 
The code implements algorithms for the calculation of the Expected Force metric on SNAP graphs in C++ and OpenMP. 

It contains:
**original serial implementation (exffunction.cpp copyright Glenn Lawyer, 2013.)
**OpenMP implementation.
**CUDA GPU implementation (our efficient algorithm, see the code in the directory ``parallel`` )

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USAGE via Makefile
"make all" will compile and test the code.

"make compile" will compile the code and create executable named ExpForce. 

"make run_test" will run a test on the graph stored in "fb_full.txt" and produce a result file "fb_full_results.txt".

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GENERAL USAGE
Once compiled, an executable named ExpForce should appear. 
Execute it with any number of filenames as arguments;

example: OMP_NUM_THREADS=16 ./ExpForce fb_full.txt 1 fb_exp.score.txt, where fb_full.txt contains a full, sorted edgelists such as
0  2
1  2
2  0
2  1


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CONTENTS
exffunction.cpp is the Glenn Lawyer original function. Calculates the expected force of a node.

main.cpp loads a graph from a text file and calculate the expected force of the nodes.

stdafx.h is an header for standard libraries and the exfccp function.

fb_full.txt is a test graph.