Interquartile Range

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()

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