[R] mosaic row and column order

Duncan Murdoch murdoch at stats.uwo.ca
Wed Oct 31 22:18:07 CET 2007

On 31/10/2007 4:33 PM, Michael Kubovy wrote:
> Dear R-helpers,
> I wasn't able to find out how to override the alphabetical ordering  
> of the rows and columns in a vcd::mosaic plot. I would like to have  
> them each ordered by numerical values in a different column of the  
> data frame that contains the contingency data.
> I would be most grateful for a pointer toward the solution.

I don't know that particular function, but most functions in R treat the 
categorical variables as factors, and use the ordering of the factor 
levels in displays. So you need to set this ordering explicitly, rather 
than let R do it automatically:

#automatic gets alphabetical order
 > x <- factor(c("red", "green", "blue"))
 > x
[1] red   green blue
Levels: blue green red

#explicit gets whatever you want
 > x <- factor(c("red", "green", "blue"), levels=c("red", "green", "blue"))
 > x
[1] red   green blue
Levels: red green blue

Duncan Murdoch

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