r - Convert data frame common rows to columns

Question

Say I have a data frame where one column is some repeating value (dates, IDs, etc). Is there a way to convert a data frame into a now data frame with columns instead of replicating rows? Basically I want to transpose something like this:

col1 col2 col3
1    aa   30
2    aa   40
3    aa   10
1    bb   20
2    bb   12
3    bb   15
1    cc   40
2    cc   31
3    cc   12

Into this:

    aa   bb   cc
1   30   20   40
2   40   12   31
3   10   15   12

Here is some code that makes a sample of the first data frame:

a <- c(rep(1:10, 3))
b <- c(rep("aa", 10), rep("bb", 10), rep("cc", 10))
set.seed(123)
c <- sample(seq(from = 20, to = 50, by = 5), size = 30, replace = TRUE)
d <- data.frame(a,b, c)

I am unsure how to transpose it.

Answer 1

a <- c(rep(1:10, 3))
b <- c(rep("aa", 10), rep("bb", 10), rep("cc", 10))
set.seed(123)
c <- sample(seq(from = 20, to = 50, by = 5), size = 30, replace = TRUE)
d <- data.frame(a,b, c)
#how to transpose it#
e<-reshape(d,idvar='a',timevar='b',direction='wide')
e