[R] ordering a boxplot

[Boris Steipe]

... just for completeness - the more concise way: (no need to go through names()).

boxplot(mydata[,order(apply(mydata,2,median))])

... or descending
boxplot(mydata[,order(-apply(mydata,2,median))])




B.



On Mar 21, 2015, at 7:04 PM, Boris Steipe <boris.steipe at utoronto.ca> wrote:

> There may be more concise ways to do this - but you are 99% there with your approach:
> try:
> 
> boxplot(mydata[,names(sort(apply(mydata,2,median)))])
> 
> B.
> 
> 
> On Mar 21, 2015, at 6:49 PM, Antonio Silva <aolinto.lst at gmail.com> wrote:
> 
>> Thanks Bill and David
>> 
>> Here goes an example
>> 
>> SP1<-c(9,6,7,8,5,8,7,5,9,7)
>> SP2<-c(1,3,4,2,4,2,5,3,2,1)
>> SP3<-c(4,6,7,5,7,8,7,6,5,4)
>> SP4<-c(5,4,3,5,2,3,4,3,4,2)
>> mydata<-data.frame(SP1,SP2,SP3,SP4)
>> rownames(mydata)<-c("ST1","ST2","ST3","ST4","ST5","ST6","ST7","ST8","ST9","ST10")
>> mydata
>> boxplot(mydata)
>> 
>> Note that this data frame does not have the format Response ~ Group. In my
>> real matrix I have up to 40 species.
>> 
>> Is there any way to have the species ordered by their median abundance (or
>> other parameter?)
>> 
>> The desired order is given by names(sort(apply(mydata,2,median)))
>> 
>> Thanks once more,
>> 
>> Antonio Olinto
>> Fisheries Institute
>> Sao Paulo, Brazil
>> 
>> 2015-03-21 15:13 GMT-03:00 William Dunlap <wdunlap at tibco.com>:
>> 
>>> You can use the reorder() function to reorder the grouping vector's
>>> factor levels according to a function of the data in each group.  E.g.,
>>> compare the following two plots:
>>> 
>>>  d <- data.frame(Response=cos(1:15), Group=rep(c("A","B","C"),c(6,5,4)))
>>>  par(mfrow=c(1,2))
>>>  boxplot(Response ~ Group, data=d)
>>>  boxplot(Response ~ reorder(Group, X=Response, FUN=median), data=d)
>>> 
>>> 
>>> Bill Dunlap
>>> TIBCO Software
>>> wdunlap tibco.com
>>> 
>>> On Fri, Mar 20, 2015 at 2:20 PM, Antonio Silva <aolinto.lst at gmail.com>
>>> wrote:
>>> 
>>>> Hello
>>>> 
>>>> I'm using a dataframe (mydata) where row names are sampling points and
>>>> column names are species in a multivariate analysis.
>>>> 
>>>> If I write boxplot(mydata) I'll have boxplots for each species abundance
>>>> in
>>>> alphabetical order.
>>>> 
>>>> How to get the boxes orderer by the median?
>>>> 
>>>> Usually for this I write
>>>> 
>>>> boxplot(value~category,at=rank(tapply(mydata$value,mydata$category,median)))
>>>> but for this to work I need a column for the categories and another column
>>>> for the values.
>>>> 
>>>> Thanks in advance, best regards.
>>>> 
>>>> Antonio Olinto
>>>> 
>>>>       [[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.
> 
> ______________________________________________
> 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.