Reshaping data frame with duplicates

Question

I have what should be a simple reshaping problem, but I can\'t figure it out. Part of my data looks like this:

foo <- structure(list(grade = c(3, 3, 4, 4,         


        

Answer 1

If you don't have any duplicates, this will work nicely:

ss <- subset(foo, var.type=='SS')
se <- subset(foo, var.type=='SE')
ss <- data.frame(grade=ss$grade,SS=ss$var.val)
se <- data.frame(grade=se$grade,SE=se$var.val)
bar <- merge(ss,se,by='grade')