[R] re ferring to data of previous rows

clion birte_2 at hotmail.com
Thu Oct 22 08:36:01 CEST 2009


thanks, it works! well, now it shows 1s instead of 0s and 2s instead of 1s,
which fine with me...but could you explain me what this function actually
does?


Gabor Grothendieck wrote:
> 
> Iff dd is your data frame then:
> 
> dd$prev <- ave(dd$of, dd$Id, FUN = function(x) c(NA, head(x, -1)))
> 
> 
> On Wed, Oct 21, 2009 at 2:55 AM, clion <birte_2 at hotmail.com> wrote:
>>
>> Dear Rlers,
>> in the following dataset I would like to insert a new column that refers
>> to
>> the data of the previous row.
>> My question is whether the probability of a female (Id) changes if she
>> had
>> given birth to a pup in the previous year. So my dataframe consists of
>> the
>> column Id, year (2003-2007 for each Id) and offspring (=of; 1-0):
>> Id   year   of
>> 1   2003   1
>> 1   2004   0
>> 1   2005   1
>> 1   2006   1
>> 1   2007   0      with 1= female (Id) gave birth to offspring (same year)
>> 2   2003   0      and 0 = female didn't pup
>> 2   2004   1
>> 2   2005   1
>> 2   2006   0
>> 2   2007   1
>> 3   2003   1
>> 3   2004   1
>> 3   2005   1
>> 3   2006   0
>> 3   2007   0
>> Now I want to add the column "offspring in the previous year -
>> yes/no(1-0)"
>> the output now should look like this:
>>
>> Id  year   of   of_inPreviousYear
>> 1   2003   1   NA
>> 1   2004   0   1
>> 1   2005   1   0
>> 1   2006   1   1
>> 1   2007   0   1
>> 2   2003   0   NA
>> 2   2004   1   0
>> 2   2005   1   1
>> 2   2006   0   1
>> 2   2007   1   0
>> 3   2003   1   NA
>> 3   2004   1   1
>> 3   2005   1   1
>> 3   2006   0   1
>> 3   2007   0   0
>>
>> any idea how I could program that?
>>
>> thanks a lot,
>> clion
>> --
>> View this message in context:
>> http://www.nabble.com/referring-to-data-of-previous-rows-tp25987364p25987364.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> 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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