[R] how to merge within range?

David Winsemius dwinsemius at comcast.net
Sat May 14 19:10:29 CEST 2011


On May 14, 2011, at 9:16 AM, Ian Gow wrote:

> If I assume that the third column in data.frame.2 is named "val"  
> then in
> SQL terms it _seems_ you want
>
> SELECT a.time, b.val FROM data.frame.1 AS a LEFT JOIN data.frame.2  
> AS b ON
> a.time BETWEEN b.start AND b.end;
>
> Not sure how to do that elegantly using R subsetting/merge,

Huh? It's just two merge()'s (... once you fix the error in the  
example.)

-- 
David

> but you might
> try a package that allows you to use SQL, such as sqldf.
>
>
> On 5/14/11 8:03 AM, "David Winsemius" <dwinsemius at comcast.net> wrote:
>
>>
>> On May 14, 2011, at 8:12 AM, René Mayer wrote:
>>
>>> Hello,
>>> how can one merge
>>
>> And what happened when you typed:
>>
>> ?merge
>>
>>> two data frames when in the second data frame one column defines the
>>> start values
>>> and another defines the end value of the to be merged range.
>>> data.frame.1
>>> time ...
>>> 13
>>> 24
>>> 35
>>> 46
>>> 55
>>> ...
>>> data.frame.2
>>> start end
>>> 24 37 ?h? ?
>>> ...
>>>
>>> should result in this
>>> 13 NA
>>> 24 ?h?
>>> 35 ?h?
>>> 46 NA
>>> 55
>>> ?
>>
>> And _why_ would that be?
>>
>>
>>> thanks,
>>> René
>>>
>>> ______________________________________________
>>> 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.
>>
>> David Winsemius, MD
>> West Hartford, CT
>>
>> ______________________________________________
>> 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.
>
>

David Winsemius, MD
West Hartford, CT



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