AS7-2 Visualizing Network Data

Section-1

§ 1.1 How many Facebook users are there in our dataset?

nrow(users)

[1] 59

what is the average number of friends per user? Hint: this question is tricky, and it might help to start by thinking about a small example with two users who are friends

2*nrow(edges)/nrow(users)

[1] 4.949

§ 1.2 Out of all the students who listed a school, what was the most common locale?

table(users$locale)

 A  B 
 6 50 

§ 1.3 Is it possible that either school A or B is an all-girls or all-boys school?

table(users$gender, users$school)

   
     A AB
  A  3  1
  B 13  1

print("no")

[1] "no"

Section-2

§ 2.1
which of the following commands will create a graph g describing our social network, with the attributes of each user correctly loaded?

library(igraph)
g = graph.data.frame(d=edges, directed=FALSE, vertices=users)
print("g = graph.data.frame(edges, FALSE, users)")

[1] "g = graph.data.frame(edges, FALSE, users)"

§ 2.2 How many connected components with at least 2 nodes are there in the graph?

plot(g, vertex.size=5, vertex.label=NA)

How many connected components with at least 2 nodes are there in the graph?

print("4")

[1] "4"

How many users are there with no friends in the network?

print("7")

[1] "7"

§ 2.3 How many users are friends with 10 or more other Facebook users in this network?

sum(degree(g) >= 10)

[1] 9

§ 2.4

V(g)$size = degree(g)/2+2
plot(g, vertex.label=NA)

What is the largest size we assigned to any node in our graph? What is the smallest size we assigned to any node in our graph?

range(V(g)$size)

[1]  2 11

Section-3

§ 3.1 What is the gender of the users with the highest degree in the graph?

V(g)$color = "black"
V(g)$color[V(g)$gender == "A"] = "red"
V(g)$color[V(g)$gender == "B"] = "gray"
plot(g, vertex.label=NA)

print("Gender B")

[1] "Gender B"

§ 3.2 Are the two users who attended both schools A and B Facebook friends with each other?

par(mar=c(1,1,1,1))
V(g)$color = "gray"
V(g)$color[V(g)$school == "A"] = "green"
V(g)$color[V(g)$school == "AB"] = "red"
plot(g, vertex.label=NA)

print("Yes")

[1] "Yes"

What best describes the users with highest degree?

print("Some, but not all, of the high-degree users attended school A")

[1] "Some, but not all, of the high-degree users attended school A"

§ 3.3

par(mar=c(1,1,1,1))
V(g)$color = "gray"
V(g)$color[V(g)$locale == "A"] = "red"
V(g)$color[V(g)$locale == "B"] = "green"
plot(g, vertex.label=NA)

The large connected component is most associated with which locale?

print("B")

[1] "B"

The 4-user connected component is most associated with which locale?

print("A")

[1] "A"

Section-4

Which igraph plotting function would enable us to plot our graph in 3-D?

library(rgl)
rglplot(g, vertex.label=NA) # not working in windows

What parameter to the plot() function would we use to change the edge width when plotting g?

plot(g, edge.width=2, vertex.label=NA)

print("edge.width")

[1] "edge.width"