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

library(plyr)
library(reshape2)
# First we add a grouping variable to deal with the duplicates
foo <- ddply(foo, .(grade, var.type), function(x) { x$group <- 1:nrow(x); x })
dcast(foo, grade + group ~ var.type, value.var= "var.val")[-2]

 grade SE  SS
1      3 47 120
2      3 12 120
3      4 46 120
4      4 14 120
5      5 46 120
6      5 16 120
7      6 47 120
8      6 20 120
9      7 46 120
10     8 46 120