Question

There are many files for which data is in the following form

year Jan Feb Mar ...........Dec
1990 x1  x2   x3           x12    
1991 y1  y2   y3           y12

.
.

2000 z1 z2 z3             z12

I want to transpose each of the rows and stack them as a column to get the time series as

x1
x2


..
x12
y1
y2
..
y12
z1
.
.
z12

I have looked at the reshape package but not clear as to how it will apply in this problem.
Any ideas for doing this in R ?

Answer 1

Perhaps melt() from the “reshape2” package is what you are looking for:

library(reshape2)
DF <- read.table(header = TRUE, text = "Year Jan Feb Mar 
1990 x1  x2   x3     
1991 y1  y2   y3 ")

DF2 <- melt(DF, id.vars="Year")
DF2[order(DF2$Year), ]
#   Year variable value
# 1 1990      Jan    x1
# 3 1990      Feb    x2
# 5 1990      Mar    x3
# 2 1991      Jan    y1
# 4 1991      Feb    y2
# 6 1991      Mar    y3