Much gratitude to Professor Ripley, Peter Dalgaard, Marc Schwartz, and Roger
Bivand.
__________________
Roger Bivand wrote that ... strsplit() returns a list - one list component
for each repeated.measures.columns element. Just pick off the one you want
with
[[]]:
as.numeric(strsplit(repeated.measures.columns, split = ",")[[1]])
which had stumped me, since that syntax fails without the [[1]]
specification.
__________________
Peter Dalgaard, who also suggested the [[1]] specification, pointed out that
scan(textConnection(x), sep=",")
will work, although that leaves you with a dangling open connection.
__________________
Marc Schwartz advised to ...
Use unlist() to take the output of strsplit() and convert it to a vector,
before coercing to numeric.
as.numeric(unlist(strsplit(repeated.measures.columns, ",")))
____________________________________
Brian D. Ripley suggested that the following looks competitive, and is quite
a bit more general (e.g. allows spaces, works with complex numbers)
eval(parse(text=paste("c(", repeated.measures.columns, ")")))
and Marc Schwartz showed that Professor Ripley's suggestion is much faster
than the competition with some system.time trials.
____________________________________
Many thanks to all.
Charles Annis, P.E.
[EMAIL PROTECTED]
phone: 561-352-9699
eFax: 614-455-3265
http://www.StatisticalEngineering.com
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Charles Annis, P.E.
Sent: Saturday, August 19, 2006 7:59 AM
To: [email protected]
Subject: [R] string-to-number
Greetings, Amigos:
I have been trying without success to convert a character string,
> repeated.measures.columns
[1] "3,6,10"
into c(3,6,10) for subsequent use.
as.numeric(repeated.measures.columns) doesn't work (likely because of the
commas)
[1] NA
Warning message:
NAs introduced by coercion
I've tried many things including
strsplit(repeated.measures.columns, split = ",")
which produces a list with only one element, viz:
[[1]]
[1] "3" "6" "10"
as.numeric() doesn't like that either.
Clearly: 1) I cannot be the first person to attempt this, and 2) I've made
this WAY harder than it is.
Would some kind soul please instruct me (and perhaps subsequent searchers)
how to convert the elements of a string into numbers?
Thank you.
Charles Annis, P.E.
[EMAIL PROTECTED]
phone: 561-352-9699
eFax: 614-455-3265
http://www.StatisticalEngineering.com
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
