Suppose I have this named vector in R:
foo=vector()
foo['a']=1
foo['b']=2
foo['c']=3
How do I most cleanly make another named vector with only elements 'a' and 'c'?
If this were a data frame with a column "name" and a column "value" I could use
subset(df, name %in% c('a', 'b'))
which is nice because subset can evaluate any boolean expression, so it is quite flexible.