[R] how to include 'NA's in xtabs?

[kjetil brinchmann halvorsen]

On 15 May 2003 at 22:34, Kosenkov Kirill wrote:

The problem with xtabs discussed in this thread is the same problem 
as was discussed for table in R1.6.2 time. The NEWS file for R1.7.0 
has:

 o	table() now allows exclude= with factor arguments (requested by
	Michael Friendly).

but (rw1070, windows XP):

> test <- c(1,2,3,1,2,3,NA,NA,1,2,3)
> test
 [1]  1  2  3  1  2  3 NA NA  1  2  3
> table(test)
test
1 2 3 
3 3 3 
> table(test, exclude=NULL)
test
   1    2    3 <NA> 
   3    3    3    2 
> test <- factor(test)
> table(test)
test
1 2 3 
3 3 3 
> table(test, exclude=NULL)
test
1 2 3 
3 3 3 

so the announced fix does'nt seem to work?

I thought the same fix could be applied to xtabs, but first rw1070
must live up to its NEWS file.

Kjetil Halvorsen

> That's ok if i do something like xtabs(~f1). Thanks.
> What about xtabs(w~f1+f2)? If i need to do crosstabulation
> and factor variables contains NA's?
> 
> I want to repeat my second question: how to use 'na.action'
> argument in xtabs? Can anybody explain, how is it works?
> 
> 
> Petr Pikal wrote:
> 
> > Hi
> > 
> > On 15 May 2003 at 0:18, Kosenkov Kirill wrote:
> > 
> > 
> >>Hello!
> >>
> >>I have a dataset with NA's in some variables (factors), for example: $
> >>P67 : Factor w/ 2 levels "-","+": NA 2 1 NA NA 2 1 1 2 NA ...
> >>
> >>I need to use 'xtabs' like
> >>xtabs(~x$P67)
> >>It works well and produces something like this:
> >>x$P67
> >>    -    +
> >>  779 1318
> >>but i want to compute NA's too, like this:
> >>x$P67
> >>    -    +   NA
> >>  779 1318  137
> > 
> > 
> > what about using summary instead of xtabs
> > 
> > 
> >>summary(ostbet$delka)
> > 
> >  159  160 NA's 
> >    5   22    3 
> > 
> > 
> >>xtabs(~ostbet$delka)
> > 
> > ostbet$delka
> > 159 160 
> >   5  22 
> > 
> > 
> > 
> > 
> > 
> >>I am trying xtabs(~x$P67, exclude=NULL) but xtabs does not compute
> >>'NA's in this case too.
> >>
> >>I do not want to transform my data (do not want to do any 
> >>substitution on NA's).
> >>
> >>How i can say 'xtabs' to compute NA-values?
> >>
> >>and second question: how to use argument 'na.action' in 'xtabs'?
> >>'xtabs' help page does not explain this.
> >>
> >>Thanks!
> >>
> >>______________________________________________
> >>R-help at stat.math.ethz.ch mailing list
> >>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> > 
> > 
> > Cheers
> > Petr Pikal
> > petr.pikal at precheza.cz
> > p.pik at volny.cz
> > 
> > 
> > 
> > 
> > .
> >
> 
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