[R] RE: Matrix to data.frame without factors
ripley@stats.ox.ac.uk
ripley at stats.ox.ac.uk
Fri Apr 12 15:27:17 CEST 2002
On Fri, 12 Apr 2002, [iso-8859-1] Mäkinen Jussi wrote:
> Sorry, my previous answer slipped away because accidental key shortcut
> typing when I was trying to copy/paste the example.
> ***
>
> Thank you for your reply. Here is a sample of my data.frame (KUNTADATA):
>
> KUNTADATA[1:10,c(6:8, 20)]
> Kunta Period Name Asunnot 1100 intarr_14
> 1 ESPOON KAUPUNKI 1993/1 14164 41336.27
> 2 ESPOON KAUPUNKI 1993/2 14164 NA
> 3 ESPOON KAUPUNKI 1994/1 14164 0.00
> 4 ESPOON KAUPUNKI 1994/2 14164 330.29
> 5 ESPOON KAUPUNKI 1995/1 14164 0.00
> 6 ESPOON KAUPUNKI 1995/2 14164 0.00
> 7 ESPOON KAUPUNKI 1996/1 14164 67277.18
> 8 ESPOON KAUPUNKI 1996/2 14164 7860.26
> 9 ESPOON KAUPUNKI 1997/1 14164 NA
> 10 ESPOON KAUPUNKI 1997/2 14164 231701.05
>
>
> So there is both type of vectors: characterical and numerical. But truly - I
There are 6 types of vectors in R: logical, integer, numeric, complex,
character and list aka `generic')!
> could just use na.to.0 when neccessary with numerical rows. But because I
> have faced this "problem" with conversions quite often I though that it
> might be a common interest to ask my question.
>
> I still cannot understand the result:
>
> > is.numeric(as.matrix(KUNTADATA[,15]))
> [1] TRUE
> > is.numeric(as.data.frame(as.matrix(KUNTADATA[,15])))
> [1] FALSE
> > mode(as.data.frame(as.matrix(KUNTADATA[1,15])))
> [1] "list"
>
> I'm sure that I just do not get the basic feature behind data.frame()
> function and that would be valuable for me and might be to somebody else as
> well.
data.frames allow colunns of different types. Matrices do not. So if
column 15 is numeric (and how can we tell, it is not in your sample!)
then as.matrix(KUNTADATA[,15]) is a one-dimensional numeric matrix.
as.data.frame(as.matrix(KUNTADATA[,15])) is a data frame with one
column. Data frames are a class, based on a list, hence the rest of
your results.
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272860 (secr)
Oxford OX1 3TG, UK Fax: +44 1865 272595
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
More information about the R-help
mailing list