PyData SV 2013 Talk by Christopher Roach

1. Intro to Network Science
Christopher Roach
19 Mar 2013
(1)

4. (3)

5. WTF?

6. Agenda

7. What is it?

8. Why now?

9. How do you use it?

10. Example

11. Complexity

12. Complexity

13. (2)

14. (2)

16. History

21. Math
(Sociology)
Computer Science

22. Network Characteristics

23. Degree Centrality

24. (i) =Cd
deg(i)
|N| − 1

25. nodes = [...]
degree = sum([is_neighbor(i, j) for j in nodes])
degree_centrality = degree/(len(nodes) - 1)

26. Closeness Centrality

27. =li
1
|N| − 1
∑
j≠i
di,j

28. (i) =Cc
1
li

29. def distance(i, j):
...
nodes = [...]
total_distance = 0
for j in nodes:
total_distance += distance(i, j)
avg_distance = total_distance/(len(nodes) - 1)
closeness_centrality = 1/avg_distance

30. Betweeness Centrality

31. (i) = (i)Cb
1
σst
∑
st
σst

32. Eigenvector Centrality
PageRank

33. geodesic (path)
eccentricity
diameter
radius
center
periphery
density

34. Example

35. http://govtrack.us

36. Demo

37. Community Detection

38. Senate Party Affiliation

39. Senate Communities

40. https://github.com/croach/pydata2013

41. References
(1) Skitter data depicting a macroscopic snapshot of Internet connectivity, with
selected backbone ISPs (Internet Service Provider) colored separately by K.
C. Claffy, Email: kc@caida.org, http://www.caida.org/publications/
papers/bydate/index.xml
(2) Running the Numbers:An American Self-Portrait by Chris Jordan,
studio@chrisjordan.com, http://chrisjordan.com
(3) Map of internet : 29 June 1999 by William R. Cheswick, ches@bell-
labs.com, http://www.cheswick.com/ches/map/gallery/index.html