[R] how to make read in a vector of 0s and 1s with no space between them

[Duncan Murdoch]

On 25/04/2010 12:52 PM, Matthew Keller wrote:
> Hi all,
>
> Probably a rudimentary question. I have a flat file that looks like
> this (the real one has ~10e6 elements):
>
> 10110100101001011101011
>
> and I want to pull that into R as a vector, but with each digit being
> it's own element. There are no separators between the digits. How can
> I accomplish this? Thanks in advance!


Is it broken up into lines at all?  Then read.fwf might be what you 
want.  If it's just a huge collection of 0s and 1s with no line breaks, 
then use readChar(filename, nchar=1) to read the individual characters, 
and later convert them to digits using ifelse(), e.g.

chars <- readChar(filename, nchar=1)
digits <- ifelse(chars=="1", 1, ifelse(chars == "0", 0, NA))

if (any(is.na(digits))) stop("not all 0s and 1s!")

Duncan Murdoch