Using column names with features of a dataframe in qplot
I have a dataset and unfortunately some of the column labels in mine dataframe
contain signs (- or +). It doesn't seem to bother dataframe
, but when I try to build this with qplot
it throws me an error:
x <- 1:5
y <- x
names <- c("1+", "2-")
mydf <- data.frame(x, y)
colnames(mydf) <- names
mydf
qplot(1+, 2-, data = mydf)
and if I enclose the column names in quotes it just gives me the category (or something like that, it gives me a graph of "1+" versus "2-" with one dot in the middle).
Can this be done easily? I looked at aes_string but didn't quite get it (at least not enough to make it work).
Thanks in advance.
PS I have searched for a solution on the internet, but cannot find anything that helps me with this (it may be related to some aspect that I do not understand), so I think it might be because it is a completely backward naming scheme. which I have: p.
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As the other answer said, you have a problem because you don't have standard names. When the solution is to avoid naming backticks
, the code names must be converted to standard form. Another motivation for converting names to regular ones, you cannot use backticks
in graphics lattice
, for example. Using gsub
, you can do this:
gsub('(^[0-9]+)[+|-]+|[+|-]+','a\\1',c("1+", "2-","a--"))
[1] "a1" "a2" "aa"
Hence, applying this to your example:
colnames(mydf) <- gsub('(^[0-9]+)[+|-]+|[+|-]+','a\\1',colnames(mydf))
qplot(a1,a2,data = mydf)
Eidt
you can use make.names
with the unique = T option
make.names(c("10+", "20-", "10-", "a30++"),unique=T)
[1] "X10." "X20." "X10..1" "a30.."
If you don't like R's naming rules, here's a custom version using gsubfn
library(gsubfn)
gsubfn("[+|-]|^[0-9]+",
function(x) switch(x,'+'= 'a','-' ='b',paste('x',x,sep='')),
c("10+", "20-", "10-", "a30++"))
"x10a" "x20b" "x10b" "a30aa" ## note x10b looks better than X10..1
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