[R] Arbirtrary column names with write.csv

[Uwe Ligges]

Rafael Laboissiere wrote:
> Is there a way to prevent write.csv to transform the column names a la
> make.names?  I mean, if I write the code:
> 
>     x <- structure (NULL)
>     x [["a+b"]] <- c (1,2)
>     write.csv (x, file = "foo.csv", row.names = FALSE, quote = FALSE)


your x is not a data.frame, hence write.csv() (or better, write.table()) 
converts your *list* x to a data.frame implicitly by using as.data.frame 
(and this tries to convert names to more regular names by make.names()). 
You can avoid it by either working on data.frames or stop the 
make.names() conversion by forcing the data.frame in advance as in:


      write.csv (as.data.frame(x, optional=TRUE), file = "foo.csv", 
row.names = FALSE, quote = FALSE)

Uwe Ligges



> I get in foo.csv:
> 
> a.b
> 1
> 2
> 
> but I want:
> 
> a+b
> 1
> 2
> 
> Any suggestions?
> 
> Cheers,
>