You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
31 lines
1.1 KiB
R
31 lines
1.1 KiB
R
# Goal: Make a time-series object using the "zoo" package
|
|
|
|
A <- data.frame(date=c("1995-01-01", "1995-01-02", "1995-01-03", "1995-01-06"),
|
|
x=runif(4),
|
|
y=runif(4))
|
|
A$date <- as.Date(A$date) # yyyy-mm-dd is the default format
|
|
# So far there's nothing new - it's just a data frame. I have hand-
|
|
# constructed A but you could equally have obtained it using read.table().
|
|
|
|
# I want to make a zoo matrix out of the numerical columns of A
|
|
library(zoo)
|
|
B <- A
|
|
B$date <- NULL
|
|
z <- zoo(as.matrix(B), order.by=A$date)
|
|
rm(A, B)
|
|
|
|
# So now you are holding "z", a "zoo" object. You can do many cool
|
|
# things with it.
|
|
# See http://www.google.com/search?hl=en&q=zoo+quickref+achim&btnI=I%27m+Feeling+Lucky
|
|
|
|
# To drop down to a plain data matrix, say
|
|
C <- coredata(z)
|
|
rownames(C) <- as.character(time(z))
|
|
# Compare --
|
|
str(C)
|
|
str(z)
|
|
|
|
# The above is a tedious way of doing these things, designed to give you
|
|
# an insight into what is going on. If you just want to read a file
|
|
# into a zoo object, a very short path is something like:
|
|
# z <- read.zoo(filename, format="%d %b %Y") |