[R] Coefficient of Variation, NA, Aggregate

[Rui Barradas]

Hello,

Just a note, you can (should?) have an argument na.rm in your function 
definition with a small modification, like this:

co.var <- function(x,na.rm=TRUE) 100*(sd(x,na.rm=na.rm)/mean(x,na.rm=na.rm))

Then you can choose to use the default TRUE or not.

Hope this helps,

Rui Barradas
Em 19-11-2012 22:50, Amanda Jones escreveu:
> Fantastic, thank you!
>
> On Mon, Nov 19, 2012 at 3:44 PM, arun <smartpink111 at yahoo.com> wrote:
>> HI,
>>
>> Your example dataset is in unreadable format.  You could use dput().
>> set.seed(5)
>>   mat1<-matrix(sample(c(1:9,NA),20,replace=TRUE),ncol=5)
>>   rowleyi<-data.frame(mat1)
>>    co.var<-function(x) 100*(sd(x,na.rm=TRUE)/mean(x,na.rm=TRUE))
>>   rowleyi<-data.frame(subspecies=rep(LETTERS[1:2],2),rowleyi)
>>
>>
>> with(rowleyi,aggregate(cbind(X1,X2,X3,X4,X5),by=list(subspecies),function(x) co.var(x)))
>>    Group.1       X1        X2       X3       X4       X5
>> 1       A       NA 70.710678       NA 20.20305 28.28427
>> 2       B 56.56854  8.318903 60.60915 47.14045  0.00000
>>
>>
>> With your aggregate()
>> aggregate(.~subspecies,data=rowleyi,co.var)
>> #  subspecies       X1       X2       X3       X4 X5
>> #1          B 56.56854 8.318903 60.60915 47.14045  0
>>
>> A.K.
>>
>>
>>
>>
>> ----- Original Message -----
>> From: Amanda Jones <akjones82 at gmail.com>
>> To: r-help at r-project.org
>> Cc:
>> Sent: Monday, November 19, 2012 4:01 PM
>> Subject: [R] Coefficient of Variation, NA, Aggregate
>>
>> Hello helpers,
>>
>> I have a two part issue. FIRSTLY, I am attempting to write a function
>> for coefficient of variation, using
>>
>>> co.var <- function(rowleyi) ( 100*sd(rowleyi)/mean(rowleyi) )  #where rowleyi is my data set, which has multiple columns and rows of data.
>> This is not working because some of my columns have NAs. When I try to use
>>
>>> co.var(rowleyi$TL, na.rm=TRUE)  #where TL is one of my column names, it gives me an error message:
>> Error in co.var(rowleyi$TL, na.rm = TRUE) :
>>    unused argument(s) (na.rm = TRUE)
>>
>> I do not know what this means. How can I get this function to work?
>> SECONDLY, how can I then get that function to work within an
>> aggragate? Do I still use
>>
>>> aggregate(. ~ subspecies, data = rowleyi, CV, na.rm=TRUE) #where subspecies is the header for rows? This has worked for mean, std.error, sd, etc.
>> Thank you!
>> Amanda Jones
>>
>> ______________________________________________
>> 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.