[R] Crosstabulation with a frequency variable

[Bert Gunter]

Yes and yes.

To be clear,

1. sum() is better.
2. xtabs is better (I just forgot about it and didn't bother to search).

Maybe the best answer is in fact,

??crosstabulation

which would have brought up xtabs(). So the moral is (to the OP),
learn how to search before posting.

Cheers,
Bert
Bert Gunter

"Data is not information. Information is not knowledge. And knowledge
is certainly not wisdom."
   -- Clifford Stoll


On Thu, Aug 13, 2015 at 8:18 AM, peter dalgaard <pdalgd at gmail.com> wrote:
>
>> On 13 Aug 2015, at 16:24 , Bert Gunter <bgunter.4567 at gmail.com> wrote:
>>
>> Well, just using base R, ...
>>
>>> with(mydata,tapply(freq,list(var1,var2),I))
>>   0  1
>> 0 11 12
>> 1 13 14
>
> If you insist on avoiding the stats package...
>
> However, I'd use sum() rather than I() to get an xtabs() workalike.
>
> -pd
>
>>
>>
>> Cheers,
>> Bert
>>
>>
>> Bert Gunter
>>
>> "Data is not information. Information is not knowledge. And knowledge
>> is certainly not wisdom."
>>   -- Clifford Stoll
>>
>>
>> On Thu, Aug 13, 2015 at 6:39 AM, Sarah Goslee <sarah.goslee at gmail.com> wrote:
>>> Hi,
>>>
>>> There are lots of ways to do it in base R, but a long time ago I got
>>> frustrated and wrote a crosstab function that did exactly what I
>>> wanted:
>>>
>>> library(ecodist)
>>> mydata <- data.frame(var1=c(0,0,1,1),var2=c(0,1,0,1),freq=c(11,12,13,14))
>>> crosstab(var1, var2, freq, data=mydata)
>>>
>>>   0  1
>>> 0 11 12
>>> 1 13 14
>>>
>>> Sarah
>>>
>>> On Thu, Aug 13, 2015 at 5:30 AM, Dean1 <web13site at yahoo.co.uk> wrote:
>>>> Hi all,
>>>>
>>>> I've had a few years experience with R, which is why this is so frustrating,
>>>> my problem seems so simple but I can't find a solution.
>>>>
>>>> I have a data frame in the following form:
>>>>
>>>> data.frame(var1=c(0,0,1,1),var2=c(0,1,0,1),freq=c(11,12,13,14))
>>>>
>>>> How do I create a crosstab with frequencies?
>>>>     0    1
>>>> 0: 11  12
>>>> 1: 13  14
>>>>
>>>>
>>>
>>> --
>>> Sarah Goslee
>>> http://www.functionaldiversity.org
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> 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 -- To UNSUBSCRIBE and more, see
>> 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.
>
> --
> Peter Dalgaard, Professor,
> Center for Statistics, Copenhagen Business School
> Solbjerg Plads 3, 2000 Frederiksberg, Denmark
> Phone: (+45)38153501
> Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com
>
>
>
>
>
>
>
>