Hi! My name is Martin and I have a problem concerning the boxplot function in R. I want my boxes to be limited by the 1st and 3rd quartile and NOT the 'hinges' values that are the default setting in R. Do anyone knows if there is any command that I could do to change this default setting? Sincerely Martin Olofsson
Martin,
I don't know of an easy way to make that change, but do note:
The two ?hinges? are versions of the first and third quartile,
i.e., close to ?quantile(x, c(1,3)/4)?. The hinges equal the
quartiles for odd n (where ?n <- length(x)?) and differ for even
n. Whereas the quartiles only equal observations for ?n %% 4 = 1? (n =
1 mod 4), the hinges do so _additionally_ for ?n %% 4 = 2? (n = 2 mod 4),
and are in the middle of two observations
otherwise.
(from the help for boxplot.stats), so it may not make any substantial
difference. You could always call boxplot.stats() on your data and see
whether the values used are close enough to the values you want to
make it not worth fiddling.
If they aren't, you'll need to look into boxplot.stats() and bxp(), I
think.
You might also look into the boxplot functions in contributed packages.
Sarah
On Fri, Jul 29, 2011 at 7:39 AM, Martin Olofsson
<martin.olofsson at zoologi.su.se> wrote:> Hi!
>
> My name is Martin and I have a problem concerning the boxplot function in
R.
> I want my boxes to be limited by the 1st and 3rd quartile and NOT the
> 'hinges' values that are the default setting in R.
> Do anyone knows if there is any command that I could do to change this
> default setting?
>
> Sincerely
>
> Martin Olofsson
>
> ______________________________________________
> 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.
>
--
Sarah Goslee
http://www.stringpage.com
http://www.sarahgoslee.com
http://www.functionaldiversity.org
Hi Martin, As Sarah said, I do not know of any way to "change the default", but you can certainly do it manually each time. Here is an example: ## generate some data set.seed(10) x <- rnorm(101) ## store boxplot results s <- boxplot(x, plot = FALSE) ## look at them s ## replace the stats with lower and upper quartile s$stats[c(2, 4), 1] <- quantile(x, c(.25, .75), TRUE, type = 7) ## plot updated boxplot bxp(s) That said, you will still have to pick what algorithm you want for your quartiles. This demonstrates the nine algorithms: t(sapply(1:9, function(i) quantile(x, c(.25, .75), TRUE, type = i))) You can find their specific details in the article: Hyndman, R. J., & Fan, Y. (1996). Sample Quantiles in Statistical Packages. The American Statistician, 50(4), 361 - 365. Hope this helps, Josh On Fri, Jul 29, 2011 at 4:39 AM, Martin Olofsson <martin.olofsson at zoologi.su.se> wrote:> Hi! > > My name is Martin and I have a problem concerning the boxplot function in R. > I want my boxes to be limited by the 1st and 3rd quartile and NOT the > 'hinges' values that are the default setting in R. > Do anyone knows if there is any command that I could do to change this > default setting? > > Sincerely > > Martin Olofsson > > ______________________________________________ > 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. >-- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles https://joshuawiley.com/