[R] Is there an equivalent * operator?

Felix Andrews felix at nfrac.org
Thu Jul 24 14:34:46 CEST 2008

If you really want to work with character strings, you could do something like
data.s1 <- data$date[grep(".*-Sep-.*", date)]

(see ?regexp for more on pattern matching)

but there are better ways to handle dates. You should convert the
character strings into Date objects: see ?Date. And check out the zoo


On Thu, Jul 24, 2008 at 8:30 PM, Williams, Robin
<robin.williams at metoffice.gov.uk> wrote:
> Hi all,
> Is there an equivalent to the general * operator in R, where * can
> represent any character?
>  I have a dataset, one column being date, date ranging between
> April-September, 97-06. I would like to be able to acquire the data for
> a specific month, say September, so that I can take average temperatures
> for the month, etc. I thought I would be able to do something like
> data.s1 <- subset(data,date=="**-Sep-**")
> data.s1
> but when I do
> data.s1
> I get "0 rows or 0-length row.names".
>  Any idea of a simple way I can perform this task?
> All dates are in the form xx-xxx-xx, EG 30-Sep-06.
> Thanks for any assistance.
> Robin Williams
> Met Office summer intern - Health Forecasting
> robin.williams at metoffice.gov.uk
>        [[alternative HTML version deleted]]
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Felix Andrews / 安福立
PhD candidate
Integrated Catchment Assessment and Management Centre
The Fenner School of Environment and Society
The Australian National University (Building 48A), ACT 0200
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