[R] Lattice dotplot with symbols sized and colored

[David Kidd]

Sundar suggested setting up a theme which I have done...

my.theme <- function() {
   theme <- col.whitebg()
   symb <- theme$superpose.symbol
   symb$col= c("red","blue","green","yellow","orange","black","purple")
   #symb$pch is c(1,3,6,0,5,16,17) by default for col.whitebg
   theme$superpose.symbol <- symb
   theme
}
trellis.par.set(theme = my.theme())
# from ?dotplot
dotplot(sporder ~ cvarorder | direct, data=sp.nc.bdrs.data,
groups = sp.nc.bdrs.data$mysign,
cex=abs(sp.nc.bdrs.data$mwZ * 0.05),
xlab="climate variables",
ylab="species",
scales = list(y = list(labels = as.character(spname),at = 1:12, cex = 0.5), 
x = list(labels = as.character(my.ylabel), at = 1:66, rot=90, cex = 0.5), 
alternating = 3))


Now if I am understanding lattice correctly setting symb$cex sets the size 
multiplier for symbols within each group but does not support the 
differential sizing of symbols for each record independently within each 
group. Hence I have tried to use a 'global' cex (after the groups 
statement), however, this has no effect on the displayed symbol size. Do I 
need to change the pch or another parameter to draw sized filled circles as 
is the default symbol for dotplot?

Thanks
Dave


----------------------------------------------------------------------------------------------
David M. Kidd
Research Assistant
School of Biology
Room 210, Sir Harold Mitchell Building
University of St. Andrews
St. Andrews, Fife
KY16 9TH
UK
http://www.st-and.ac.uk/~bugs/dave/dave.htm
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