Aim
I am aiming to make a multiple Sankey in R using the googleVis
package. The output should look similar to this:
Data
I've created some dummy data in R:
set.seed(1)
source <- sample(c("North","South","East","West"),100,replace=T)
mid <- sample(c("North ","South ","East ","West "),100,replace=T)
destination <- sample(c("North","South","East","West"),100,replace=T) # N.B. It is important to have a space after the second set of destinations to avoid a cycle
dummy <- rep(1,100) # For aggregation
dat <- data.frame(source,mid,destination,dummy)
aggdat <- aggregate(dummy~source+mid+destination,dat,sum)
What I've tried so far
I can build a Sankey with 2 variables fine if I have just a source and destination, but not a middle point:
aggdat <- aggregate(dummy~source+destination,dat,sum)
library(googleVis)
p <- gvisSankey(aggdat,from="source",to="destination",weight="dummy")
plot(p)
The code produces this:
Question
How do I modify
p <- gvisSankey(aggdat,from="source",to="destination",weight="dummy")
to accept the mid
variable as well?
Function
gvisSankey
does accept mid-levels directly. These levels have to be coded in underlying data.Now, we'll reshape original data:
Data frame
datSM
summarises number of units from Source to Mid.Data frame
datMD
summarises number of units from Mid to Destination. This data frame will be added to the final data frame. Data frame need to beungroup
and have samecolnames
.As the
datMD
is appended as the last one,gvisSankey
will recognise the middle step automatically.Here is the plot: