[R] Interquartile Range

[Bert Gunter]

To be precise:

paste(round(quantile(x,0.25),0),round(quantile(x,0.75),0),sep="-")

is an expression that evaluates to a character string:
"round(quantile(x,.25),0) - round(quantile(x,0.75),0)"

no matter what the argument of your function, x. Hence

return(paste(...)) will return this exact character string and never
evaluates x.


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 Tue, Apr 19, 2016 at 8:34 AM, William Dunlap via R-help
<r-help at r-project.org> wrote:
>> That didn't work Jim!
>
> It always helps to say how the suggestion did not work.  Jim's
> function had a typo in it - was that the problem?  Or did you not
> change the call to ddply to use that function.  Here is something
> that might "work" for you:
>
>  library(plyr)
>
>  data <- data.frame(groupColumn=rep(1:5,1:5), col1=2^(0:14))
>  myIqr <- function(x) {
>      paste(round(quantile(x,0.25),0),round(quantile(x,0.75),0),sep="-")
>  }
>  ddply(data, ~groupColumn, summarise, col1_myIqr=myIqr(col1),
> col1_IQR=stats::IQR(col1))
>  #  groupColumn col1_myIqr col1_IQR
>  #1           1        1-1        0
>  #2           2        2-4        1
>  #3           3      12-24       12
>  #4           4    112-320      208
>  #5           5  2048-8192     6144
>
> The important point is that
>     paste(round(quantile(x,0.25),0),round(quantile(x,0.75),0),sep="-")
> is not a function, it is an expression.   ddplyr wants functions.
>
>
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
>
> On Tue, Apr 19, 2016 at 7:56 AM, Michael Artz <michaeleartz at gmail.com>
> wrote:
>
>> That didn't work Jim!
>>
>> Thanks anyway
>>
>> On Mon, Apr 18, 2016 at 9:02 PM, Jim Lemon <drjimlemon at gmail.com> wrote:
>>
>> > Hi Michael,
>> > At a guess, try this:
>> >
>> > iqr<-function(x) {
>> >
>> return(paste(round(quantile(x,0.25),0),round(quantile(x,0.75),0),sep="-")
>> > }
>> >
>> > .col3_Range=iqr(datat$tenure)
>> >
>> > Jim
>> >
>> >
>> >
>> > On Tue, Apr 19, 2016 at 11:15 AM, Michael Artz <michaeleartz at gmail.com>
>> > wrote:
>> > > Hi,
>> > >   I am trying to show an interquartile range while grouping values
>> using
>> > > the function ddply().  So my function call now is like
>> > >
>> > > groupedAll <- ddply(data
>> > >                  ,~groupColumn
>> > >                  ,summarise
>> > >                  ,col1_mean=mean(col1)
>> > >                  ,col2_mode=Mode(col2) #Function I wrote for getting
>> the
>> > > mode shown below
>> > >
>> > >  ,col3_Range=paste(as.character(round(quantile(datat$tenure,c(.25)))),
>> > > as.character(round(quantile(data$tenure,c(.75)))), sep = "-")
>> > >                  )
>> > >
>> > > #custom Mode function
>> > > Mode <- function(x) {
>> > >   ux <- unique(x)
>> > >   ux[which.max(tabulate(match(x, ux)))]
>> > > }
>> > >
>> > > I am not sre what is going wrong on my interquartile range function, it
>> > > works on its own outside of ddply()
>> > >
>> > >         [[alternative HTML version deleted]]
>> > >
>> > > ______________________________________________
>> > > 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.
>> >
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> 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.
>>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> 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.