Question

I’m looking to take a data series like the one contained here:

http://robjhyndman.com/tsdldata/roberts/beards.dat

…and load it into a zoo time series object in R. There is no table of date information, but it lists that it’s regular, annual, and starts in y=1866. This is what I’m attempting…

beard <- read.zoo('http://robjhyndman.com/tsdldata/roberts/beards.dat', 
header=FALSE, 
index.column=0,
start="1866-01-01",
format="%Y", 
skip=4)

It mostly works, but ignores the “start” argument from zooreg.

So, I have a fine solution that reads this, then changes the index like so…

index(beard) <- as.Date(paste(seq(1866,1911, by=1),'-01-01',sep=''), format="%Y-%m-%d")

…but this would be slicker if there were an argument in read.zoo() that let me do this in a single call. Am I missing it, or is it a two-step problem?

Answer 1

Specify a custom FUN= like this:

URL <- 'http://robjhyndman.com/tsdldata/roberts/beards.dat'
toDate <- function(x) as.Date(as.yearmon(x) + 1865)
beard <- read.zoo(URL, index = 0, skip = 4, FUN = toDate)