Question

one quick question

picture a data frame like

data=data.frame(x=c(1,2,3), y=c(4,5,6), Genes=c("AHS;AKS;AHS","AHS;IO","HU"))

so i want to plot x and y

plot(x,y) 

and do the label for the dots like this

text(data$x+0.2,data$y+0.2,labels=data$Genes)

BUT i dont want to use all arguments from the genes column ONLY the first one (e.g. before the “;”)
Can u please help me with that?
This is only an example, i have already read my data in with read.delim, so i cannot do a specific “read in” with string separation.

Answer 1

As per my comment, you can use gsub to do this:

gsub('^([A-Z]+);.*$', '\\1', data$Genes)

You could also use strsplit:

unlist(lapply(strsplit(data$Genes, ';'), '[', 1))

But that’s yucky…

Its also probably worth mentioning the stringr package which collects a lot of these string munging functions in to a single place with predictable syntax and names.