How to create a network chart? - r

Question

I am trying to use networkD3::forceNetwork to create a chart of employers and colleges from which employers hire employees.
Right now, I have something like this:
forceNetwork(Links= Links, Nodes= netDf ,
Source = 'collegeName', Target = 'organizationName', Value='count',
NodeID = 'collegeName', Group = 'organizationName')
But the output doesn't look as expected. What I would like to have, is:
One bubble for each college
One bubble for each employer
Colleges connected to employer, with number of employers (count) mapped to the width of the connection lines.
Colleges are never connected to each other, and the same holds for employers.
This is the dataset I am using netDf:
structure(list(collegeName = c("college1", "college1", "college2",
"college3", "college3", "college3", "college4", "college5", "college5",
"college6", "college6", "college6", "college7", "college7", "college7",
"college8", "college9", "college10", "college10", "college11"
), organizationName = c("employer2", "employer3", "employer2",
"employer1", "employer2", "employer3", "employer2", "employer2",
"employer3", "employer1", "employer2", "employer3", "employer1",
"employer2", "employer3", "employer2", "employer2", "employer2",
"employer3", "employer2"), count = c(858, 176, 461, 201, 2266,
495, 430, 1992, 290, 127, 1754, 549, 136, 2839, 686, 638, 275,
1388, 387, 188), group = c(2, 3, 2, 1, 2, 3, 2, 2, 3, 1, 2, 3,
1, 2, 3, 2, 2, 2, 3, 2)), .Names = c("collegeName", "organizationName",
"count", "group"), row.names = c(NA, -20L), class = "data.frame")
And this is the Links dataset:
structure(list(collegeName = c(0, 0, 1, 2, 2, 2, 3, 4, 4, 5,
5, 5, 6, 6, 6, 7, 8, 9, 9, 10), organizationName = c(1, 2, 1,
0, 1, 2, 1, 1, 2, 0, 1, 2, 0, 1, 2, 1, 1, 1, 2, 1), count = c(858,
176, 461, 201, 2266, 495, 430, 1992, 290, 127, 1754, 549, 136,
2839, 686, 638, 275, 1388, 387, 188), group = c(2, 3, 2, 1, 2,
3, 2, 2, 3, 1, 2, 3, 1, 2, 3, 2, 2, 2, 3, 2)), .Names = c("collegeName",
"organizationName", "count", "group"), row.names = c(NA, -20L
), class = "data.frame")
Also, would it be possible to map a 4th variable to the bubble size? Say for instance that I want to map count to che size of the bubble pertaining the employees, how can I do that?

Answer 1

I think your Links and Nodes data frames do not meet the requirements as specified in ?forceNetwork. Instead, you could do:
library(networkD3)
set.seed(1)
nodes <- data.frame(Label = unique(c(netDf[,1], netDf[,2])))
nodes$Group <- as.factor(substr(nodes$Label, 1, 3))
nodes <- merge(
nodes,
aggregate(count~organizationName, netDf, sum),
by.x="Label", by.y="organizationName",
all.x=TRUE
)
nodes$count[is.na(nodes$count)] <- 1
links <- transform(netDf,
Source = match(netDf$collegeName, nodes$Label)-1,
Target = match(netDf$organizationName, nodes$Label)-1
)
forceNetwork(
Links = transform(links, count = count/min(count)),
Nodes = nodes,
Source = 'Source',
Target = 'Target',
Value='count',
NodeID = 'Label',
Group = "Group",
Nodesize = "count",
legend = TRUE,
opacity = 1,
radiusCalculation = JS("Math.log(d.nodesize)+6")
)