CODEWITHSUNDEEP
rstackreshape2melt
user4846627
user4846627

Reputation: 43

Unstacking a data frame

I have a data frame which looks like this:

d <- c("a", "b", "c", "a", "b", "c", "a", "b", "c")
par <- c("a1", "a2", "a3", "a4", "a5", "a6", "a7", "a8", "a9")
df1 <- as.data.frame(cbind(id, par))

I would like it to look like this:

a <- c("a1", "a4", "a7")
b <- c("a2", "a5", "a8")
c <- c("a3", "a6", "a7")
df2 <- data.frame(rbind(a, b, c))

Upvotes: 1

Views: 2372

Answers (2)

akrun
akrun

Reputation: 886948

You could do this with unstack

as.data.frame(t(unstack(df1,par~id)))
#  V1 V2 V3
#a a1 a4 a7
#b a2 a5 a8
#c a3 a6 a9

Or using dcast after creating a sequence column for the 'id' group.

library(data.table)#v1.9.5
dcast(setDT(df1)[, ind:= 1:.N, id], id~ind, value.var='par')

Upvotes: 1

user4846627
user4846627

Reputation: 43

I have solved this as below, seems too messy though 

id <- c("a", "b", "c", "a", "b", "c", "a", "b", "c")
par <- c("a1", "a2", "a3", "a4", "a5", "a6", "a7", "a8", "a9")
df1 <- as.data.frame(cbind(id, par))


ids <- levels(df1$id)

newdf <- list()

for ( i in 1:length(ids)){
tempdf <- df1[df1$id == ids[i],]
id <- tempdf[1,1]
parcels <- tempdf[,2]
row <- cbind(as.character(id), t(as.character(parcels)))
tempdf <- as.data.frame(row)
newdf[[i]] <- tempdf
}

df3 <- do.call(rbind.fill, newdf)

Upvotes: 0

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