Venn diagram with product tags

Question

Suppose I have two vectors

foo <- c('a','b','c','d')
baa <- c('a','e','f','g')

Does anyone know a way to create a Venn diagram, but vector elements are rendered inside the diagram.

How so? (made in powerpoint)

Answer 1

Package Usage RAM:

library(RAM)
foo <- c('a','b','c','d')
baa <- c('a','e','f','g')
group.venn(list(foo=foo, baa=baa), label=TRUE, 
    fill = c("orange", "blue"),
    cat.pos = c(0, 0),
    lab.cex=1.1)

Answer 2

Quick solution using the functions venn.diagramfrom the package VennDiagram. Labels (counters) are hard-coded into functions, so they cannot be changed using function arguments. But for a simple example, you can change it grobsyourself.

library(VennDiagram)

# your data
foo <- c('a','b','c','d')
baa <- c('a','e','f','g')

# Generate plot
v <- venn.diagram(list(foo=foo, baa=baa),
                  fill = c("orange", "blue"),
                  alpha = c(0.5, 0.5), cat.cex = 1.5, cex=1.5,
                  filename=NULL)

# have a look at the default plot
grid.newpage()
grid.draw(v)

# have a look at the names in the plot object v
lapply(v,  names)
# We are interested in the labels
lapply(v, function(i) i$label)

# Over-write labels (5 to 7 chosen by manual check of labels)
# in foo only
v[[5]]$label  <- paste(setdiff(foo, baa), collapse="\n")  
# in baa only
v[[6]]$label <- paste(setdiff(baa, foo)  , collapse="\n")  
# intesection
v[[7]]$label <- paste(intersect(foo, baa), collapse="\n")  

# plot  
grid.newpage()
grid.draw(v)

What produces

Obviously, this method will quickly get out of hand with a large number of categories and intersections.