[R] read.table(..., header == FALSE, colClasses = )

Benjamin Tyner
Tue, 24 Oct 2017 11:21:33 -0000

Jeff,

Thank you for your reply. The intent was to construct a minimum
reproducible example. The same warning occurs when the 'file' argument
points to a file on disk with a million lines. But you are correct, my
example was slightly malformed and in fact gives an error under R
version 3.2.2. Please allow me to try again; in older versions of R,

 ?? > read.table(file = textConnection("a\t3.14"), header = FALSE,
colClasses = c(x = "character", y = "numeric"),
sep="\t")
 ? ?? V1?? V2
 ?? 1? a 3.14

(with no warning). As of version 3.3.0,

 ?? > read.table(file = textConnection("a\t3.14"), header = FALSE,
colClasses = c(x = "character", y = "numeric"),
sep="\t")
 ? ?? V1?? V2
 ?? 1? a 3.14
 ?? Warning message:
 ?? In read.table(file = textConnection("a\t3.14"), header = FALSE,? :
 ? ?? not all columns named in 'colClasses' exist

My intent was not to complain but rather to learn more about best
practices regarding the names attribute.

Regards

Ben



On 10/23/2017 08:51 PM, Jeff Newmiller wrote:
> You are constructing the equivalent of a two-line data file, and
complaining that it is not treating it like it was one line. If it did used to
accept this silently [skeptical] then I for one am glad it produces a warning
now.