[R] Please, need help with a plot

[Ben Bolker]

Victor F Seabra <vseabra <at> uol.com.br> writes:

> 
> 
>    Please, I wonder if someone knows how to add the
>    less than or equal to symbol in the plot generated by the code below:
>    var1<-c('age <= 3','age <= 7','age <= 10','age <= 11','age <= 20','age <=
>    25','age <= 30','age <= 45','age <= 50','age < 55','age >= 55')
>    var2<-c(3.8,5.4,3.7,3.8,5.9,6.4,7.2,8.4,10.5,1.3,0.7)
>    table1<-data.frame(var1, var2)
>    plot(x=table1$var2,y=1:11,xlim=c(0,20),pch=20)
>    text(x=table1$var2,y=1:11,table1$var1,pos=4)
>    title(x=15,y=5,expression("how  to  substitute  the  < = with the " <=
>    "symbol"),font=5)
>    Please, note that the data must come from a table (not manually fed in a
>    text command)
>    I received help yesterday and learned a fix using
>    \u2264, eval, parse, and sprintf  but the symbols generated by this fix are
>    not exported to an .EPS file
>    Kind regards,


  This is a little bit more 'magic' than I would like, but seems
to work. Perhaps someone else can suggest a cleaner solution.

ages <- gsub("[^0-9]+","",table1$var1)
rel <- gsub("age\\s*([=<>]+)\\s*[0-9]+","\\1",table1$var1,perl=TRUE)

with(table1,plot(var2,1:11,xlim=c(0,20),pch=20))
invisible(with(table1,
     mapply(function(x,y,a,r) {
       text(x=x,y=y,
            switch(r,
                   `<=`=bquote(age <= .(a)),
                   `<`=bquote(age < .(a)),
                   `>=`=bquote(age >= .(a))),
            pos=4)},
       var2,1:11,ages,rel)))