[R] read.delim problem with trailing spaces

[John Fox]

Dear Mike,

This is a trap, but it's not a bug, and to "correct" it wouldn't be
appropriate, I think. That is, the string ". " wasn't declared as NA. One
could do the following to avoid the problem:

> read.csv("c:/temp/test.txt", na.strings=".", strip.white=TRUE)
            income   imr region oilexprt imr80 gnp80 life
Afghanistan     75 400.0      4        0 185.0    NA 37.5
Algeria        400  86.3      2        1  20.5  1920 50.7
Argentina     1191  59.6      1        0  40.8  2390 67.1
Australia     3426  26.7      4        0  12.5  9820 71.0
Austria       3350  23.7      3        0  14.8 10230 70.4
Bangladesh     100 124.3      4        0 139.0   120   NA
Belgium       3346  17.0      3        0  11.2 12180 70.6
Benin           81 109.6      2        0 109.6   300   NA
Bolivia        200  60.4      1        0  77.3   570 49.7
Brazil         425 170.0      1        0  84.0  2020 60.7
Britain       2503  17.5      3        0  12.6  7920 72.0
Burma           73 200.0      4        0 195.0   180 42.3

Regards,
 John



> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of 
> Michael Friendly
> Sent: Wednesday, October 06, 2004 8:18 AM
> To: R-help
> Subject: [R] read.delim problem with trailing spaces
> 
> I'm trying to read a comma delimited dataset that uses '.' 
> for NA.  I found that if the last field on a line was a missing '.'
> it was not read as NA, but just a '.', and the life variable 
> was made a factor.  The data looks like this,
> 
> income,imr,region,oilexprt,imr80,gnp80,life
> Afghanistan,75,400.0,4,0,185.0,.,37.5
> Algeria,400,86.3,2,1,20.5,1920,50.7
> Argentina,1191,59.6,1,0,40.8,2390,67.1
> Australia,3426,26.7,4,0,12.5,9820,71.0
> Austria,3350,23.7,3,0,14.8,10230,70.4
> Bangladesh,100,124.3,4,0,139.0,120,.
> Belgium,3346,17.0,3,0,11.2,12180,70.6
> Benin,81,109.6,2,0,109.6,300,.
> Bolivia,200,60.4,1,0,77.3,570,49.7
> Brazil,425,170.0,1,0,84.0,2020,60.7
> Britain,2503,17.5,3,0,12.6,7920,72.0
> Burma,73,200.0,4,0,195.0,180,42.3
>   ...
> 
> and I used
>  > nations <-
> read.delim("~/sasuser/data/nations2.dat",na.strings=".",row.na
> me=1,sep=",",header=TRUE)
> 
> > nations[1:10,]
>             income   imr region oilexprt imr80 gnp80 life
> Afghanistan     75 400.0      4        0 185.0    NA 37.5
> Algeria        400  86.3      2        1  20.5  1920 50.7
> Argentina     1191  59.6      1        0  40.8  2390 67.1
> Australia     3426  26.7      4        0  12.5  9820 71.0
> Austria       3350  23.7      3        0  14.8 10230 70.4
> Bangladesh     100 124.3      4        0 139.0   120   .
> Belgium       3346  17.0      3        0  11.2 12180 70.6
> Benin           81 109.6      2        0 109.6   300   .
> Bolivia        200  60.4      1        0  77.3   570 49.7
> Brazil         425 170.0      1        0  84.0  2020 60.7
> > summary(nations$life)
>   .  27.0 31.6 32.0 32.6 34.5 35.0 36.0 36.7 36.9 37.1 37.2 
> 37.5 38.5 38.8 40.5
>    2    1    1    1    1    1    2    1    1    1    1    1   
>  1    3    1    1
> 40.6 41.0 41.2 42.3 43.5 43.7 44.9 45.1 46.8 47.5 47.6 49.0 
> 49.7 49.9 50.0 50.5
>    1    6    1    4    1    1    1    1    1    3    1    3   
>  1    1    2    1
> 
> 
> After much hair-pulling, I discovered that the data lines for 
> Bangladesh and Benin contained a trailing space after the 
> '.'.  Removing those made the problem go away, but that 
> shouldn't happen and I wonder if this is
> still a potential problem for others.   I'm using R 1.8.1.
> 
> -Michael
> 
> -- 
> Michael Friendly     Email: friendly at yorku.ca 
> Professor, Psychology Dept.
> York University      Voice: 416 736-5115 x66249 Fax: 416 736-5814
> 4700 Keele Street    http://www.math.yorku.ca/SCS/friendly.html
> Toronto, ONT  M3J 1P3 CANADA
> 
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