Re: [R] colClasses = "Date" in read.delim, how to pass date-format?

From: Prof Brian Ripley <>
Date: Tue 19 Apr 2005 - 02:53:07 EST

You are confusing class "Date" (part of R) with class "dates" (part of package chron). There is no as() method for class "dates", so you can't do this. You can read the column as character (not factor) and convert later, but it sounds like the `huge amount of memory (and time)' is in fact taken by package chron.

On Mon, 18 Apr 2005, Christoph Lehmann wrote:

> I have a huge data-set with one column being of type date.
> Of course I can import the data using this column as "factor" and then
> convert it later to dates, using:
> sws.bezuege$FaktDat <- dates(as.character(sws.bezuege$FaktDat),
> format = c(dates = "d.m.y"))
> But the conversion requires a huge amount of memory (and time), therefore I
> would like to use colClasses = c("Date"). My question is:
> since I have format = c(dates = "d.m.y"), how can I pass this option to
> read.delim(..., colClasses = c("Date")) ?

Brian D. Ripley,        
Professor of Applied Statistics,
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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Received on Tue Apr 19 03:00:15 2005

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