Interquartile Range
I already found a solution, you suggested I try to find a non hacky solution, which was not really my priority. I should have declined politely, which I will do now. Or, ifyou just want me to post reproducible code because you are bored or because you like solving problems then let me know and I will accommodate. You have been helpful and I wouldnt mind in that case. Also, IQR was not a help from the beginning. If it supplies one value, then its not even a candidate to be helpful for my problem. I already talked about the format i was looking for. I dont think I violated any posting guideline, I asked for help, and people pointed me in a direction and it helped me. Thanks again, I appreciate it.
On Apr 19, 2016 10:53 PM, "Bert Gunter" <bgunter.4567 at gmail.com> wrote:
??? IQR returns a single number.
IQR(rnorm(10))
[1] 1.090168 To your 2nd response: "I could have used average, min, max, they all would have returned the same thing., " I can only respond: huh?? Are all your values identical? You really need to provide a small reproducible example as requested by the posting guide -- I certainly don't get it, and I'm done guessing. Maybe others will see what I am missing and say something useful. I clearly can't. 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 5:29 PM, Michael Artz <michaeleartz at gmail.com> wrote:
Again, IQR returns two both a .25 and a .75 value and it failed, which is why I didn't use it before. Also, the first function just returns tha
same
value repeating. Since they are the same, before the second call, using
the
mode function is just a way to grab one value. I could have used average, min, max, they all would have returned the same thing. Mike On Tue, Apr 19, 2016 at 7:24 PM, Marc Schwartz <marc_schwartz at me.com>
wrote:
Hi, Jumping into this thread mainly on the point of the mode of the distribution, while also supporting Bert's comments below on theory. If the vector 'x' that is being passed to this function is an integer vector, then a tabulation of the integers can yield a 'mode', presuming
of
course that there is only one unique mode. You may have to decide how
you
want to handle a multi-modal discrete distribution. If the vector 'x' is continuous (e.g. contains floating point values), then a tabulation is going to be problematic for a variety of reasons. In that case, prior discussions on this point, have yielded the
following
estimation of the mode of a continuous distribution by using:
Mode <- function(x) {
D <- density(x)
D$x[which.max(D$y)]
}
where the second line of the function gets you the value of 'x' at the
maximum of the density estimate. Of course, there is still the
possibility
of a multi-modal distribution and the nuances of which kernel is used,
etc.,
etc. Food for thought. Regards, Marc Schwartz
On Apr 19, 2016, at 7:07 PM, Bert Gunter <bgunter.4567 at gmail.com>
wrote:
Well, instead of your functions try:
Mode <- function(x) {
tabx <- table(x)
tabx[which.max(tabx)]
}
and use R's IQR function instead of yours.
... so I still don't get why you want to return a character string
instead of a value for the IQR;
and the mode of a sample defined as above is generally a bad estimator
of the mode of the distribution. To say more than that would take me
too far afield. Post on stats.stackexchange.com if you want to know
why (if it's even relevant).
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 4:25 PM, Michael Artz <michaeleartz at gmail.com
wrote:
Hi,
Here is what I am doing
notGroupedAll <- ddply(data
,~groupColumn
,summarise
,col1_mean=mean(col1)
,col2_mode=Mode(col2) #Function I wrote for getting
the
mode shown below
,col3_Range=myIqr(col3)
)
groupedAll <- ddply(data
,~groupColumn
,summarise
,col1_mean=mean(col1)
,col2_mode=Mode(col2) #Function I wrote for getting
the
mode shown below
,col3_Range=Mode(col3)
)
#custom Mode function
Mode <- function(x) {
ux <- unique(x)
ux[which.max(tabulate(match(x, ux)))]
#the range function
myIqr <- function(x) {
paste(round(quantile(x,0.375),0),round(quantile(x,0.625),0),sep="-")
}
}
Here is what I am doing!! :)
On Tue, Apr 19, 2016 at 2:57 PM, William Dunlap <wdunlap at tibco.com>
wrote:
If you show us, not just tell us about, a self-contained example someone might show you a non-hacky way of getting the job done. (I don't see an argument to plyr::ddply called 'transform'.) Bill Dunlap TIBCO Software wdunlap tibco.com On Tue, Apr 19, 2016 at 12:18 PM, Michael Artz <michaeleartz at gmail.com> wrote:
Oh thanks for that clarification Bert! Hope you enjoyed your
coffee!
I ended up just using the transform argument in the ddply function.
It
worked and it repeated, then I called a mode function in another call to ddply that summarised. Kinda hacky but oh well! On Tue, Apr 19, 2016 at 12:31 PM, Bert Gunter <bgunter.4567 at gmail.com> wrote:
... and I'm getting another cup of coffee... -- 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 10:30 AM, Bert Gunter <bgunter.4567 at gmail.com> wrote:
NO NO -- I am wrong! The paste() expression is of course evaluated. It's just that a character string is returned of the form "something - something". I apologize for the confusion. -- 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 10:25 AM, Bert Gunter <bgunter.4567 at gmail.com> wrote:
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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______________________________________________ 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.
______________________________________________ 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.