Hi r-help,
A very simple question for which I have not been able to find an answer
in the docs:
How can I merge two character strings?
I am searching for the equivalent of the (non-existing) stringmerge
function illustrated below:
s1 <- "R-"
s2 <- "project"
stringmerge(s1,s2)
[1] "R-project"
Claus

look at ?paste(), e.g.,

s1 <- "R-"
s2 <- "project"
paste(s1, s2, sep = "")

Best,
Dimitris

Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/16/336899
Fax: +32/16/337015
Web:
~m0390867/dimitris.htm

Message
From: "Claus Hindsgaul" <claush (AT) mek (DOT) dtu.dk>
To: <r-help (AT) stat (DOT) math.ethz.ch>
Sent: Tuesday, August 16, 2005 1:01 PM
Subject: [R] How to merge two strings

Hi r-help,

A very simple question for which I have not been able to find an
answer
in the docs:

How can I merge two character strings?

I am searching for the equivalent of the (non-existing) stringmerge
function illustrated below:
>
>s1 <- "R-"
>s2 <- "project"
>stringmerge(s1,s2)
[1] "R-project"
>>
>
Claus

Thank you all!
Paste() was just the function I needed to know!

Claus

tir, 16 08 2005 kl. 13:06 +0200, skrev Dimitris Rizopoulos:
look at ?paste(), e.g.,

s1 <- "R-"
s2 <- "project"
paste(s1, s2, sep = "")

Best,
Dimitris

Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/16/336899
Fax: +32/16/337015
Web:
~m0390867/dimitris.htm

Message
From: "Claus Hindsgaul" <claush (AT) mek (DOT) dtu.dk>
To: <r-help (AT) stat (DOT) math.ethz.ch>
Sent: Tuesday, August 16, 2005 1:01 PM
Subject: [R] How to merge two strings

Hi r-help,

A very simple question for which I have not been able to find an
answer
in the docs:

How can I merge two character strings?

I am searching for the equivalent of the (non-existing) stringmerge
function illustrated below:
>
>s1 <- "R-"
>s2 <- "project"
>stringmerge(s1,s2)
[1] "R-project"
>>
>
Claus

Tue, 16 Aug 2005, Barry Rowlingson wrote:

Claus Hindsgaul wrote:
>Thank you all!
>Paste() was just the function I needed to know!
>
sprintf:

s1 <- "R-"
s2 <- "project"
sprintf("%s%s",s1,s2)
[1] "R-project"

It seems to be much faster:

unix.time(for(i in 1:100000){junk=sprintf("%s%s",s1,s2)})
[1] 1.12 0.00 1.12 0.00 0.00
unix.time(for(i in 1:100000){junk=paste(s1,s2,sep='')})
[1] 5.90 0.01 5.92 0.00 0.00

Not that I imagine string concatenation will ever be a bottleneck
worth optimising but there it is. A well-constructed sprintf() call may
be more readable than a pastey mess though, with all its fiddly commas
and quotes - contrived example:

sprintf("%s://%s%s/%s",scheme,host,dir,file)
[1] ""

paste(scheme,'://',host,dir,'/',file,sep='')
[1] ""

which do you prefer?

That's actually the reason we have the enhanced sprintf that we do
nowadays: to enable readable (and translatable) error messages to be
written via gettextf.