[R] Dealing with null values Aggregate function

[Jonathan Daily]

Furthermore, aggregate passes extra arguments to FUN, so explicit
declaration of na.rm = T can be done in the call to aggregate
directly:

aggregate(cbind(v1, v2) ~ v3, data = testDF, FUN = mean, na.rm = T)

HTH,
Jon

On Tue, May 17, 2011 at 5:22 AM, Jannis <bt_jannis at yahoo.de> wrote:
> Andy,
>
>
> have a look at ?mean. The na.omit argument set to TRUE should solve your
> problem. The use in aggregate would be something like:
>
> aggregate(x = testDF, by = list(testDF$v3), FUN = function(x)
> mean(x,na.rm=TRUE))
>
>
>
> HTH
> Jannis
>
>
>
> On 05/17/2011 04:27 AM, Andrew McFadden wrote:
>>
>> Hi R users
>>
>> I trying to some aggregate statistics on a very large dataset. The null
>> values are causing a problem. I would like to calculate aggregate values
>> for groups. I am just no sure how to deal with the "" I would ideally
>> like them to ignored ie if there is only 1 value over several columns
>> than that value would be the summary statistic.
>>
>> I have put the following example together to show my problem.
>>
>> testDF<- data.frame(v1 = c(1,3,5,7,8,3,5,NA,4,5,7,9),
>>                      v2 = c(11,33,55,77,88,33,55,NA,44,55,77,99),
>>
>> v3=c("red","red","red","red","red","red","blue","blue","blue","blue","bl
>> ue","blue"))
>>
>> aggregate(x = testDF, by = list(testDF$v3), FUN = "mean")
>>
>> For this example I would like to get a mean value for red (v1=4.5; v1=5)
>> and blue (v1=49.5; v2=55)
>>
>> Thank you in advance.
>>
>> Andy
>>
>> Andrew McFadden MVS BVSc
>> Incursion Investigator
>> Investigation&  Diagnostic Centres - Wallaceville Biosecurity New
>> Zealand Ministry of Agriculture and Forestry
>>
>> Phone 04 894 5600 Fax 04 894 4973 Mobile 029 894 5611 Postal address:
>> Investigation and Diagnostic Centre- Wallaceville Box 40742 Ward St
>> Upper Hutt
>>
>>
>>
>>
>>
>> This email message and any attachment(s) is intended solely for the
>> addressee(s)
>> named above. The information it contains is confidential and may be
>> legally
>> privileged.  Unauthorised use of the message, or the information it
>> contains,
>> may be unlawful. If you have received this message by mistake please call
>> the
>> sender immediately on 64 4 8940100 or notify us by return email and erase
>> the
>> original message and attachments. Thank you.
>>
>> The Ministry of Agriculture and Forestry accepts no responsibility for
>> changes
>> made to this email or to any attachments after transmission from the
>> office.
>>
>>        [[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.
>>
>
> ______________________________________________
> 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.
>



-- 
===============================================
Jon Daily
Technician
===============================================
#!/usr/bin/env outside
# It's great, trust me.