[R] Counting

Ashta sewashm at gmail.com
Tue Oct 20 18:42:31 CEST 2009


Hi Bill and all,


On Tue, Oct 20, 2009 at 12:09 PM, William Dunlap <wdunlap at tibco.com> wrote:
>> From: r-help-bounces at r-project.org
>> [mailto:r-help-bounces at r-project.org] On Behalf Of Peter Ehlers
>> Sent: Tuesday, October 20, 2009 8:48 AM
>> To: Ashta
>> Cc: R help
>> Subject: Re: [R] Counting
>>
>> How about
>>
>>   unch <- aggregate(x2==x1, by = list(x1=x1), FUN = sum)
>>   chgd <- aggregate(x2!=x1, by = list(x1=x1), FUN = sum)
>>
>>   -Peter Ehlers
>
> When I hear 'count' I think first of the table() function.
> E.g.,
>   > d<-data.frame(x1=c(1,1,0,0,0,1,0), x2=c(1,0,1,1,0,1,1))
>   > with(d, table(x1, x1==x2))
>
>   x1  FALSE TRUE
>     0     3    1
>     1     1    2
> or
>   > with(d, table(x1, factor(x1==x2,labels=c("Changed","Unchanged"))))
>
>   x1  Changed Unchanged
>     0       3         1
>     1       1         2
> or use dimnames<- to change the labels on the table itself.

 This works very well for  numeric.
 How about if the factors are character such  as F and M  (male and female) ?




>
> Bill Dunlap
> Spotfire, TIBCO Software
> wdunlap tibco.com
>
>>
>> Ashta wrote:
>> > Hi All,
>> >
>> > Assume that I have the following data set  with two variables and I
>> > want count the number of observation with identical values
>> and number
>> > of time each factor changed from x1 to x2.
>> >
>> > x1  x2
>> >  1    1
>> >  1    0
>> >  0    1
>> >  0    1
>> >  0    0
>> >  1    1
>> >  0    1
>> >
>> > The output should be
>> > x1  changed
>> >                       0   3    # has changed 3 times
>> >                       1   1    # has changed 1 time
>> > x1 unchanged
>> >                       0  1    # has unchanged only 1 time
>> >                       1  2     # has unchanged 2 times
>> >
>> > Can someone help me how to do it in R?
>> >
>> > Thanks in advance
>> >
>> > ______________________________________________
>> > R-help at r-project.org mailing list
>> > 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.
>> >
>> >
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> 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.
>>
>




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