On 18/12/2010, David Winsemius <dwinsem...@comcast.net> wrote: > > On Dec 18, 2010, at 7:01 AM, e-letter wrote: > >> Readers, >> >> I am trying to use the function dotchart. The data is: >> >>> testdot >> category values1 values2 values3 values4 >> 1 a 10 27 56 709 >> 2 b 4 46 47 208 >> 3 c 5 17 18 109 >> 4 d 6 50 49 308 >> >> The following error occurs >> >>> dotchart(testdot,groups=testdot[,2]) >> Error in dotchart(testdot, labels = testdot[, 1], groups = testdot[, >> 2]) : >> 'x' must be a numeric vector or matrix >> >> According to my understanding (clearly wrong!) of the documentation >> for dotchart (accessed from the manual in section 'graphics'), columns >> of data can be selected by 'groups' for subsequent plotting. > > The misunderstanding is in how you see the grouping information versus > how R expects it. R generally expects such data in what is called > "long" format, i.e. there will be one values columns and a category > column. There are various ways to change the arrangement of your data. > The function stack(), the function reshape(), or probably most > commonly the function melt from reshape2 being the typical chosen > routes. >
Reshape and melt are not installed (version251) so for this task manual rearrangement data is easier. > require(reshape) Loading required package: reshape [1] FALSE Warning message: there is no package called 'reshape' in: library(package, lib.loc = lib.loc, character.only = TRUE, logical = TRUE, > library(reshape) Error in library(reshape) : there is no package called 'reshape' > mdot<-melt(dot) Error: could not find function "melt" However before doing so why this is relevant because of the alternative creation objects 'testdot1'. Aren't these objects suitable, since a (undesireable) graph was produced? >> The >> objective is to be able to create a dot chart where each row is >> labelled according to the row names in the 'category' column and two >> columns can be selected, e.g. 'values1' and 'values2'. Then I tried: >> >>> testdot1<-testdot[,1] >>> testdot2<-testdot[,2] >>> testdot3<-testdot[,3] >>> dotchart(c(testdot2,testdot3),labels=testdot1) > > See if this is more to your liking: > > require(reshape) # I'm not sure why I have reshape_0.8.3 rather than > reshape2 loaded > # I'm pretty sure Hadley would prefer that people > use pkg:reshape2 > mdot <- melt(dot) > dotchart(mdot$value, groups=mdot$category, labels=mdot$variable) > # OR more readable > with(mdot, dotchart(value, groups=category, labels=variable) ) > > I'm not sure I got the roles of "values" and "category" correct, but > it should be a simple matter to switch them in the dotcghart call if > that is your pleasuRe. > I don't have dotcghart either. ______________________________________________ R-help@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.
