R help - May 2011 - why does scan(gzfile("file"), what='integer') import data as mode "character" ?

Hi all,

My code:

x <- scan(gzfile("file"),what='integer')

x is imported, but as mode "character" rather than
"integer". I know I
can do as.integer() when importing, but am still trying to figure out
why the above occurs. When I do
summary(as.integer(x)), there are no NAs introduced by coercion, so
the vector really is all integer.

Also, is the above code the fastest for importing a very long zipped
data, with 132 million rows and 1 column?

Thanks in advance,

Matt


-- 
Matthew C Keller
Asst. Professor of Psychology
University of Colorado at Boulder
www.matthewckeller.com

Try giving what an example of an integer instead
of the character string "integer".  E.g.,
   what = 0L
or
   what = integer(0)

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com  
> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of Matthew Keller
> Sent: Sunday, May 29, 2011 4:28 PM
> To: r help
> Subject: [R] why does scan(gzfile("file"),
what='integer')
> import data as mode "character" ?
> 
> Hi all,
> 
> My code:
> 
> x <- scan(gzfile("file"),what='integer')
> 
> x is imported, but as mode "character" rather than
"integer". I know I
> can do as.integer() when importing, but am still trying to figure out
> why the above occurs. When I do
> summary(as.integer(x)), there are no NAs introduced by coercion, so
> the vector really is all integer.
> 
> Also, is the above code the fastest for importing a very long zipped
> data, with 132 million rows and 1 column?
> 
> Thanks in advance,
> 
> Matt
> 
> 
> -- 
> Matthew C Keller
> Asst. Professor of Psychology
> University of Colorado at Boulder
> www.matthewckeller.com
> 
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