[R] About data manipulation

[Bert Gunter]

A reproducible example was not provided, but I think what is wanted is
either ?tapply or ?ave; e.g.

within(DF, means <- ave(total, note, month, FUN = mean))


Cheers,
Bert
Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Sat, Nov 26, 2016 at 3:42 PM, P Tennant <philipt900 at iinet.net.au> wrote:
> Hi,
>
> It may help that:
>
> aggregate(DF$total, list(DF$note, DF$id, DF$month), mean)
>
> should give you means broken down by time slice (note), id and month. You
> could then subset means for GA or GB from the aggregated dataframe.
>
> Philip
>
> On 27/11/2016 3:11 AM, lily li wrote:
>>
>> Hi R users,
>>
>> I'm trying to manipulate a dataframe and have some difficulties.
>>
>> The original dataset is like this:
>>
>> DF
>> year   month   total   id     note
>> 2000     1         98    GA   1
>> 2001     1        100   GA   1
>> 2002     2         99    GA   1
>> 2002     2         80    GB   1
>> ...
>> 2012     1         78    GA   2
>> ...
>>
>> The structure is like this: when year is between 2000-2005, note is 1;
>> when
>> year is between 2006-2010, note is 2; GA, GB, etc represent different
>> groups, but they all have years 2000-2005, 2006-2010, 2011-2015.
>> I want to calculate one average value for each month in each time slice.
>> For example, between 2000-2005, when note is 1, for GA, there is one value
>> in month 1, one value in month 2, etc; for GB, there is one value in month
>> 1, one value in month 2, between this time period. So later, there is no
>> 'year' column, but other columns.
>> I tried the script: DF_GA = aggregate(total~year+month,data=subset(DF,
>> id==GA&note==1)), but it did not give me the ideal dataframe. How to do
>> then?
>> Thanks for your help.
>>
>>         [[alternative HTML version deleted]]
>>
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>
>
> ______________________________________________
> 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.