[R] Identifying time series

Achim Zeileis
2004-10-04T13:42:15Z

On Mon, 4 Oct 2004 09:00:46 -0400  John DeAngelis wrote:

>
>
>
> Hello,
>
> I am currently attempting to introduce R at my company and am trying
> to import time series data from a text file into R to graph. The
> format of the text file is in date, data (e.g.,  20040929 3.361).

You can read in such a file, e.g., via
R> x <- read.table(file = "mydata.txt", colClasses =
c("character",
     "numeric"))

> My problem is that I do
> not know how to get R to recognize the first column as a business date
> series.

You can do that via strptime(), e.g.,

R> strptime(x[,1], "%Y%m%d")

(and possibly convert then to POSIXct or Date).

Then you can create an irregular time series, e.g. via package its or
via package zoo:

R> y <- zoo(x[,2], strptime(x[,1], "%Y%m%d"))
R> plot(y)

hth,
Z

> Or at the very least, I am unable to find a function that will
> grap the second column (y-axis) against the date series (x-axis). If
> you could tell me how to graph this type of data, I would greatly
> appreciate it. Thank you.
>
>
> Regards,
>
> John DeAngelis
>
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