[R] inserting zero instances with zeroes in a matrix

[Simon Pickett]

Thanks Gregor and Henrique for the eloquent and masterful replies,

These solutions have saved me hours (maybe even days) of work in the future,
I am very grateful. :-)

Simon.


----- Original Message ----- 
From: "Gabor Grothendieck" <ggrothendieck at gmail.com>
To: "Henrique Dallazuanna" <wwwhsd at gmail.com>
Cc: "Simon Pickett" <simon.pickett at bto.org>; <r-help at r-project.org>
Sent: Thursday, December 18, 2008 11:51 AM
Subject: Re: [R] inserting zero instances with zeroes in a matrix


> Try this:
>
> as.data.frame(xtabs(count ~., d.f))
>
>
> On Thu, Dec 18, 2008 at 6:25 AM, Henrique Dallazuanna <wwwhsd at gmail.com> 
> wrote:
>> Try this:
>>
>> with(d.f,
>>    {merge(data.frame(house = rep(unique(house), each =
>> length(unique(pet))),
>>             pet = unique(pet)), d.f, by = c("house", "pet"), all = TRUE)
>>      }
>>     )
>>
>> On Thu, Dec 18, 2008 at 8:58 AM, Simon Pickett 
>> <simon.pickett at bto.org>wrote:
>>
>>> Hi all,
>>>
>>> Suppose I had the below example where a survey was carried out recording
>>> the number of each type of pet in each house
>>>
>>> count<-c(2,1,2,1,2,3,4)
>>> house<-c("house1","house1","house2","house3","house4","house4","house4")
>>> pet<-c("dogs","cats","dogs","dogs","budgie","cat","hamster")
>>> d.f<-data.frame(house,pet,count)
>>>
>>> How would I acheive a dataframe that had every instance of house in 
>>> column
>>> 1, all possible pets in column 2 and counts in column 3 like this...
>>>
>>> newhouse<-rep(unique(house),1,each=4)
>>> newpets<-rep(unique(pet),4)
>>> newcount<-c(2,1,0,0,2,0,0,0,1,0,0,0,0,3,2,4)
>>> newdf<-data.frame(newhouse,newpets,newcount)
>>>
>>> Is there a way of doing this without creating a new matrix and using
>>> programming loops?
>>>
>>> Thanks in advance, Simon.
>>>
>>>
>>>
>>>        [[alternative HTML version deleted]]
>>>
>>> ______________________________________________
>>> 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.
>>>
>>
>>
>>
>> --
>> Henrique Dallazuanna
>> Curitiba-Paraná-Brasil
>> 25° 25' 40" S 49° 16' 22" O
>>
>>        [[alternative HTML version deleted]]
>>
>>
>> ______________________________________________
>> 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.
>>
>>
>
>