[R] Unexpected behaviour as.data.frame

[Jan van der Laan]

Thanks. I also noticed myself minutes after sending my message to the 
list. My 'please ignore my question it was just a stupid typo' message 
was sent with the wrong account and is now awaiting moderation.

However, my other question still stands: what is the 
preferred/fastest/simplest way to create a data.fame with given column 
types and dimensions?

Regards,
Jan


On 05/15/2011 04:43 PM, Bert Gunter wrote:
> In your post, you're missing the final "s" on the stringsAsFactors
> argument in the d1 assignment. When I typed it correctly, it works as
> expected.
>
> -- Bert
>
> On Sun, May 15, 2011 at 4:25 AM, Jan van der Laan<rhelp at eoos.dds.nl>  wrote:
>> I use the following code to create two data.frames d1 and d2 from a list:
>> types<- c("integer", "character", "double")
>> nlines<- 10
>> d1<- as.data.frame(lapply(types, do.call, list(nlines)),
>> stringsAsFactor=FALSE)
>> l2<- lapply(types, do.call, list(nlines))
>> d2<- as.data.frame(l2, stringsAsFactors=FALSE)
>>
>> I would expect d1 and d2 to be the same, however, in d1 the second column is
>> a factor while in d2 it is a character (which I would expect):
>>
>>> str(d1)
>> 'data.frame':   10 obs. of  3 variables:
>>   $ c.0L..0L..0L..0L..0L..0L..0L..0L..0L..0L.: int  0 0 0 0 0 0 0 0 0 0
>>   $ c........................................: Factor w/ 1 level "": 1 1 1 1
>> 1 1 1 1 1 1
>>   $ c.0..0..0..0..0..0..0..0..0..0.          : num  0 0 0 0 0 0 0 0 0 0
>>> str(d2)
>> 'data.frame':   10 obs. of  3 variables:
>>   $ c.0L..0L..0L..0L..0L..0L..0L..0L..0L..0L.: int  0 0 0 0 0 0 0 0 0 0
>>   $ c........................................: chr  "" "" "" "" ...
>>   $ c.0..0..0..0..0..0..0..0..0..0.          : num  0 0 0 0 0 0 0 0 0 0
>>
>>
>> As different but related question: I use the commands above to create an
>> 'empty' data.frame with specified column types and dimensions. I need this
>> data.frame to pass on to my c++ routines. Is there a more simple/elegant way
>> of creating this data.frame?
>>
>> Regards,
>>
>> Jan
>>
>>
>> PS:
>> I am running R on 64 bit Ubuntu 11.04:
>>
>>> sessionInfo()
>> R version 2.12.1 (2010-12-16)
>> Platform: x86_64-pc-linux-gnu (64-bit)
>>
>> locale:
>>   [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
>>   [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
>>   [5] LC_MONETARY=C              LC_MESSAGES=en_US.UTF-8
>>   [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
>>   [9] LC_ADDRESS=C               LC_TELEPHONE=C
>> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>>
>> attached base packages:
>> [1] stats     graphics  grDevices utils     datasets  methods   base
>>
>> ______________________________________________
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>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>