Task 1. visualize all network ties in krack_full using the adjacency
matrix. color edges according to friendship, advice, and reports-to
ties

Task 2. cluster nodes by community membership using the friendship
network, and replot the adjacency matrix with nodes belonging to the
same communities placed close to each other.
construct a new variable, tie strength, which is the combination of
friendship, advice, and reports-to ties this counts the types of
relationships between two nodes
## IGRAPH clustering edge betweenness, groups: 11, mod: 0.099
## + groups:
## $`1`
## [1] "1" "2" "4" "6" "12" "17" "21"
##
## $`2`
## [1] "3" "14" "15" "19"
##
## $`3`
## [1] "5" "11"
##
## $`4`
## + ... omitted several groups/vertices
## [1] "1" "2" "3" "4" "5" "6" "7" "8" "9" "10" "11" "12" "13" "14" "15"
## [16] "16" "17" "18" "19" "20" "21"

Task 3. use radial tree to visualize the reports-to network, and a
treemap to show the advice network.
in the treemap, set size proportional to ego’s degrees from the
advice and reports-to networks

