[R] End of line marker?

[Duncan Murdoch]

On 04/03/2010 10:32 PM, David Winsemius wrote:
> On Mar 4, 2010, at 9:47 PM, jonas garcia wrote:
> 
>> When I opened the file with a hex-editor, the problematic character  
>> turned out to be “1a”
>>  I am attaching a sample DAT file with 3 lines (the second line is  
>> the one with the undesirable character).
>>
>> The furthest I could get was through readBin:
>>
>>> tmp<- readBin("new.dat", what = "raw", n=100000000)
>>   [1] 30 32 3a 33 35 3a 33 32 2c 20 34 34 30 33 2c 20 33 37 2e 31 31  
>> 34 2c 2d 32 30 2e 38 33 36 2c 31
>>  [33] 35 35 2e 39 2c 30 30 2e 37 36 2c 31 31 35 36 0d 0a 30 32 3a 33  
>> 35 3a 33 35 2c 20 34 34 33 32 2c
>>  [65] 20 33 37 2e 31 31 34 2c 2d 32 30 2e 38 33 36 2c 31 35 35 2e 38  
>> 2c 1a 30 2e 38 31 2c 31 31 35 37
>>  [97] 0d 0a 30 32 3a 33 35 3a 33 39 2c 20 34 34 36 37 2c 20 33 37 2e  
>> 31 31 34 2c 2d 32 30 2e 38 33 36
>> [129] 2c 31 35 35 2e 38 2c 30 30 2e 38 31 2c 31 31 35 38
>>
>>
>>> tmp[87]
>> [1] 1a
> 
> I got a different "interpretation" of that character when I let R look  
> at it. And I cannot figure out why \032 should be causing problems??? :

Hex 1a and octal 032 both correspond to Ctrl-Z, which is the MSDOS EOF 
marker.  I forget whether R's text reading routines pay attention to 
that, or whether it's the C runtime, but it makes sense that it would 
cause problems on Windows.

Duncan Murdoch

> 
>  > tmporg <- readLines(con="/Users/davidwinsemius/Library/Mail  
> Downloads/new.dat")
> Warning message:
> In readLines(con = "/Users/davidwinsemius/Library/Mail Downloads/ 
> new.dat") :
>    incomplete final line found on '/Users/davidwinsemius/Library/Mail  
> Downloads/new.dat'
> 
>  > tmporg
> [1] "02:35:32, 4403, 37.114,-20.836,155.9,00.76,1156"
> [2] "02:35:35, 4432, 37.114,-20.836,155.8,\0320.81,1157"
> [3] "02:35:39, 4467, 37.114,-20.836,155.8,00.81,1158"
>  > gsub("\\\032", ' ', tmporg)
> [1] "02:35:32, 4403, 37.114,-20.836,155.9,00.76,1156" "02:35:35, 4432,  
> 37.114,-20.836,155.8, 0.81,1157"
> [3] "02:35:39, 4467, 37.114,-20.836,155.8,00.81,1158"
> 
> 
>  > read.table(textConnection(gsub("\\\032", ' ', tmporg) ) ,sep=",")
>          V1   V2     V3      V4    V5   V6   V7
> 1 02:35:32 4403 37.114 -20.836 155.9 0.76 1156
> 2 02:35:35 4432 37.114 -20.836 155.8 0.81 1157
> 3 02:35:39 4467 37.114 -20.836 155.8 0.81 1158
> 
> Looks like gsub might work well .... as long as you can get agreement  
> on what the character really is.
> 
>  > sessionInfo()
> R version 2.10.1 RC (2009-12-09 r50695)
> x86_64-apple-darwin9.8.0
> 
> locale:
> [1] en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8
> 
> attached base packages:
> [1] splines   stats     graphics  grDevices utils     datasets   
> methods   base
> 
> other attached packages:
> [1] Design_2.3-0    Hmisc_3.7-0     survival_2.35-7
> 
> loaded via a namespace (and not attached):
> [1] cluster_1.12.1  grid_2.10.1     lattice_0.17-26 tools_2.10.1
>