R: Create nested list from IDs in character vector - r

Question

I have a character vector of hierarchical IDs like this one:
ids <- c("0","1","2","3","1.1","1.2","1.3","2.1","2.2","2.11","2.21","2.22")
The hierarchical structure is as follows:
1
1.1
1.2
1.3
2
2.1
2.11
2.2
2.21
2.22
I want to use diagonalNetwork() from the networkD3 package to visualize this hierarchy. But diagonalNetwork() requires a nested list defining each nodes children like this one:
l <- list(name = "0",
children = list(
list(name = "1",
children = list(
list(name = "1.1"),
list(name = "1.2"),
list(name = "1.3")
)
),
list(name = "2",
children = list(
list(name = "2.1",
children = list(
list(name = "2.11")
)
),
list(name = "2.2",
children = list(
list(name = "2.21"),
list(name = "2.22")
)
)
)
)
)
)
My actual set of ids is much larger and deeper (up to 6 digits long), so I need a way to create this nested list automatically. I started with creating a data.frame that stores the ids' digits in several columns like this one:
df <- data.frame(root = 0,
a = c( 1, 1, 1, 1, 2, 2, 2, 2, 2, 2),
b = c(NA, 1, 2, 3,NA, 1, 1, 2, 2, 2),
c = c(NA,NA,NA,NA,NA,NA, 1,NA, 1, 2))
But I can't think of a way to get any further with my concern.
Is there a more promising approach?

Answer 1

Here is a possible solution based on recursive function. And it is by no means a fast solution but should work for you.
library(network3D)
findChildren <- function(pa, ids) {
lapply(ids, function(ch){
if(grepl(paste("^", pa, sep = ""), ch) && ch != pa &&
nchar(gsub("\\.", "", ch)) == nchar(gsub("\\.", "", pa)) + 1)
{
childrenTmp = Filter(Negate(is.null), findChildren(ch, ids))
if(length(childrenTmp) != 0) list(name = ch, children = childrenTmp)
else list(name = ch)
}
}
)
}
myList <- list(name = "0",
children = Filter(
function(x){nchar(x$name) == 1 },
lapply(ids[-1], function(id) {
childrenTmp = Filter(Negate(is.null), findChildren(id, ids))
if(length(childrenTmp) != 0) list(name = id, children = childrenTmp)
else list(name = id)
}
)
)
)
diagonalNetwork(myList)