Because by default blank fields aren't considered to be missing in factors
but they are in integer vectors.

> f1<-factor(c(1,2,"",3,4))
> f1
[1] 1 2   3 4
Levels:  1 2 3 4

I think you can fix this by specifying na.strings=c("NA","")

On 26/09/06, Anupam Tyagi <AnupTyagi@yahoo.com> wrote:
>
> Hi,
>
> The colClasses seem to be supressing 'NA' vlaues. How do I fix this?
>
> R script and first 5 lines of output is below.
>
> File "test2.dat" has blanks that are read as "NA" when I do not use
> 'colClasses', but as blanks when I use 'colClasses'.
>
> temp.df <- read.fwf("test2.dat", width=c(10,1,1,1,1,2,2,3,3,1),
> col.names=c
> ("psu","losewt","maintain","fewcal","phyact","age","income","weight",
> "wtdesire","gender"),
>
> colClasses=c("factor","factor","factor","factor","factor","numeric","factor",
> "numeric","numeric","factor"),
> nrows=270000, comment.char="")
>
> temp.df
>            psu losewt maintain fewcal phyact age income weight wtdesire
> gender
> 1   2003009323      2        2                52
> 05    220      220      1
> 2   2003005181      2        1      2      2  58
> 08    165      145      2
> 3   2003015942      2        1      4      1  76
> 05    142      130      2
> 4   2003011406      2        1      3      1  43
> 03    110      110      2
> 5   2003006786      1               4      1  49
> 06    178      145      2
>
> ? why am I not getting missing values when I use 'colClasses'?
>
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>



-- 
=================================
David Barron
Said Business School
University of Oxford
Park End Street
Oxford OX1 1HP

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