Such a simple thing but I had trouble finding this.

Your reply is close but one more step is needed — recognizing whether or not the returned value is an integer, a hint I got from Prof. Brian Ripley as per
http://markmail.org/search/list:r-project?q=split+string

In the meantime, I also created and documented two functions,
string2vector and vector2string
that take my R-programming to a level where I am more comfortable. Here they are:

string2vector = function(string=”ch-2 \t sec-7\tex-5″, SS=”\t”, type=”char”)
# This procedure splits a string and assigns substrings to an R-vector.
# The split is controlled by the string separator SS (default value: SS=”\t”).
# Here we convert a binary string into a binary vector:
# let binS = “10011″
# then binV = string2vector(binS, SS=”", type=”int”)
# Here we convert a string into a vector of substrings:
# let strS = “I am done”
# then vecS = string2vector(strS, SS=” “, type=”char”)
#
# LIMITATION: The function interprets all substrings either as of type
# “int” or “char”. A function that interprets the type of each
# substring dynamically may one day be written by an R-guru.
#
# Franc Brglez, Wed Dec 9 14:19:16 EST 2009
{
qlist = strsplit(string, SS) ; qvector = qlist[[1]]
n = length(qvector) ; xvector = NULL
for (i in 1:n) {
if (type == “int”) {
tmp = as.integer(qvector[i])
} else {
tmp = qvector[i]
}
xvector = c(xvector, tmp)
}
return(xvector)
} # string2vector

vector2string = function(vector=c(“ch-2″, “sec-7″, “ex-5″), SS=”_”, type=”char”)
# This procedure converts values from a vector to a concatenation of substrings
# separated by user-specified string separator SS (default value: SS=”_”).
# Each substring represents a vector component value, either as a numerical
# value or as an alphanumeric string.
# Here we convert a binary vector to a binary string representing an integer:
# let binV = c(1,0,0,1)
# then strS = vector2string(binV, type=”int”)
# Here we convert a binary vector to string representing a binary sequence:
# let binV = c(1,0,0,1)
# then seqS = vector2string(binV, SS=” “, type=”char”)
# Here we convert a vector of substrings to colon-separated string:
# let subsV = c(“I”, “am”, “done”)
# then strS = vector2string(subsV, SS=”:”, type=”char”)
#
# LIMITATION: The function interprets all substrings in the vector either as of
# type “int” or “char”. A function that interprets the type of each
# substring dynamically may one day be written by an R-guru.
#
# Franc Brglez, Wed Dec 9 15:43:59 EST 2009
{
if (type == “int”) {
string = paste(strsplit(paste(vector), ” “), collapse=”")
} else {
n = length(vector) ; nm1 = n-1 ; string = “”
for (i in 1:nm1) {
tmp = noquote(vector[i])
string = paste(string, tmp, SS, sep=”")
}
tmp = noquote(vector[n])
string = paste(string, tmp, sep=”")
}
return(string)
} # vector2string

Sorry for the delay. Would the following work for you?

> bar = foo[[1]]
> bar[4]
[1] “1″
> bar[7]
[1] “0″

> binNum = “1001110″
> foo = noquote(strsplit(binNum, NULL[[1]]))
> foo
[[1]]
[1] 1 0 0 1 1 1 0
> foo[4]
[[1]]
NULL

How would you create, from binNum, a “vector” binSeq = c(1,0,0,1,1,1,0) so that
> binSeq[4]
[1] 1
> binSeq[7]
[1] 0
>
MANY THANKS — franc