How to have title in R Vennerable Venn Diagram?

Question

I cannot find anything in documentation here. Code

library("Vennerable")
data(StemCell)
Vstem <- Venn(StemCell)
Vstem3 <- Vstem[, c("OCT4", "SOX2", "NANOG")]
tl <- "masi"
plot(Vstem3, doWeights = TRUE, type = "circles")

Tried unsuccessfully

• plot(..., main = tl)
• plot(..., title = tl)
• plot(...); title(tl)
• plt <- plot(...); title(plt, tl)

Fig. 1 Wrong output without title

R: 3.3.1
OS: Debian 8.5

Answer 1

user20650 answer in comments summarised here. Try (1-2) and choose what fits best.

1. The plot method is based on the grid package so the normal base R plot approaches to add a title won't work. Looking at the arguments of args(Vennerable:::plotVenn), there doesn't seem a way to add a title and unhelpfully the plots do not return a grid object. So you can just draw a title on the plot window with the following

   grid.text("masi", y=0.9, gp=gpar(col="red", cex=2))
   

2. As an alternative method, you could grab the grob and then use grid.arrange to plot the title

   gridExtra::grid.arrange(grid::grid.grabExpr(plot(Vstem3, doWeights = TRUE, 
      type = "circles")), top="masi")
   

The grid.arrange way adds the title as a separate grob, and then they are arranged in two rows. So when resizing the graphics window, it still appears above the plot. This won't be true when drawing straight on the window (as in the first version). Note: you do not need to use gridExtra, you could do this in grid.

Fig. 1 Output from (1), Fig. 2 Output from (2)

I think (1) could be better with more adjustments, but now (2) is better.