Re: [R] search path question
Prof Brian Ripley wrote:
You could do this via a search_file() connection wrapper, but there is a
problem with ensuring connections get closed (which on.exit does here).
I'm not sure exactly what you mean by a 'search_file() connection
wrapper', but I have realised that its probably a better idea to write a
function that checks a search path for a file and then returns that file:
search_file =
function(name,path=options()$scanpath,...){
for(p in path){
file=file.path(p,name)
if(file.exists(file)){
return(file)
}
}
return(name)
}
Then you can use that in any filename-using function:
options(scanpath=c(/data1,/data2,/etc))
search_file(passwd)
[1] /etc/passwd
passwd = read.table(search_file(passwd),sep=:)
record = scan(search_file(passwd),what='')[1]
Barry
__
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] search path question
I meant essentially the same thing but returning file(fixed_up_name).
You can vectorize this BTW:
search_file - function(name, path=getOption(scanpath))
{
fp - c(name, file.path(path, name)) # better to use direct name first
fp - fp[file.exists(fp)]
if(length(fp)) file(fp[1]) else stop(name, not found)
}
Shortly things like
read.table(search_file(passwd))
will close the unnamed connection for you.
On Wed, 30 May 2007, Barry Rowlingson wrote:
Prof Brian Ripley wrote:
You could do this via a search_file() connection wrapper, but there is a
problem with ensuring connections get closed (which on.exit does here).
I'm not sure exactly what you mean by a 'search_file() connection
wrapper', but I have realised that its probably a better idea to write a
function that checks a search path for a file and then returns that file:
search_file =
function(name,path=options()$scanpath,...){
for(p in path){
file=file.path(p,name)
if(file.exists(file)){
return(file)
}
}
return(name)
}
Then you can use that in any filename-using function:
options(scanpath=c(/data1,/data2,/etc))
search_file(passwd)
[1] /etc/passwd
passwd = read.table(search_file(passwd),sep=:)
record = scan(search_file(passwd),what='')[1]
Barry
__
R-help@stat.math.ethz.ch 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.
--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UKFax: +44 1865 272595
__
R-help@stat.math.ethz.ch 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.
[R] search path question
Hi R users, Is there a simple function that can add a folder into current R search path? For example, suppose my current work directory is D:\work, but my input files are stored in folder C:\inFiles\, I know I can change work directory or add C:\inFiles\ before files name when I scan them, but I don't want to do that. I want to find a function that can simply add C:\inFiles\ into R's search path, so that we I scan a file R will go to all the search paths to find it. In matlab, path(path,C:\inFiles) will do this job, I'm just wondering if there is a similar function in R can do this job. Thanks, zhiliang [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch 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.
Re: [R] search path question
Yes, it is.
The original is here
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/92829.html
However, it requires some modifications.
Here they are. Sorry, I can test it only in Windows.
search.source - function(file, path=Sys.getenv(PATH), ...)
{
for(p in strsplit(path,.Platform$path.sep)[[1]]) {
fp - file.path(p, f)
if(file.exists(fp)) return(source(fp, ...))
}
stop(file , sQuote(file), not found)
}
Try also looking here.
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/92821.html
Zhiliang Ma wrote:
Is there a simple function that can add a folder into current R search
path?
For example, suppose my current work directory is D:\work, but my input
files are stored in folder C:\inFiles\, I know I can change work
directory or add C:\inFiles\ before files name when I scan them, but I
don't want to do that. I want to find a function that can simply add
C:\inFiles\ into R's search path, so that we I scan a file R will go to
all the search paths to find it. In matlab, path(path,C:\inFiles) will
do
this job, I'm just wondering if there is a similar function in R can do
this
job.
--
View this message in context:
http://www.nabble.com/search-path-question-tf3833821.html#a10855885
Sent from the R help mailing list archive at Nabble.com.
__
R-help@stat.math.ethz.ch 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.
[R] search path question
Hi R users, Is there a simple function that can add a folder into current R search path? For example, suppose my current work directory is D:\work, but my input files are stored in folder C:\inFiles\, I know I can change work directory or add C:\inFiles\ before files name when I scan them, but I don't want to do that. I want to find a function that can simply add C:\inFiles\ into R's search path, so that we I scan a file R will go to all the search paths to find it. In matlab, path(path,C:\inFiles) will do this job, I'm just wondering if there is a similar function in R can do this job. Thanks, zhiliang [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch 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.
Re: [R] search path question
Zhiliang Ma wrote:
I want to find a function that can simply add
C:\inFiles\ into R's search path, so that we I scan a file R will go to
all the search paths to find it. In matlab, path(path,C:\inFiles) will do
this job, I'm just wondering if there is a similar function in R can do this
job.
Something like this (not extensively tested):
`sscan` -
function(name, path=options()$scanpath,...){
for(p in path){
file=file.path(p,name)
if(file.exists(file)){
return(scan(file,...))
}
## last resort..
return(scan(name,...))
}
}
Then do:
options(scanpath=/tmp)
and then:
sscan(foo.data)
will look for /tmp/foo.data first, then if that fails it will do the
'last resort' which is to look in the current directory.
My worry is that this will bite you one day - if you have two files
with the same name, it will get the first one in your scanpath - one day
this will not be the one you think it is
Note this only works with 'scan' - you'll have to do the same thing
for read.table, source, etc etc if you want them to behave with a search
path too. Unless there's a lower-level approach. But that really will
bite you!
Barry
Barry
__
R-help@stat.math.ethz.ch 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.
Re: [R] search path question
On Tue, 29 May 2007, Zhiliang Ma wrote: Hi R users, Is there a simple function that can add a folder into current R search path? This works for adding libraries to your search path, but I don't think it would work for finding data files outside of your getwd() quite as you'd like: .libPaths(c(/home/foo/R/library,.libPaths())) For example, suppose my current work directory is D:\work, but my input files are stored in folder C:\inFiles\, I know I can change work directory or add C:\inFiles\ before files name when I scan them, but I don't want to do that. I want to find a function that can simply add C:\inFiles\ into R's search path, so that we I scan a file R will go to all the search paths to find it. In matlab, path(path,C:\inFiles) will do this job, I'm just wondering if there is a similar function in R can do this job. Thanks, zhiliang [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch 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. -- Dr. David Forrest [EMAIL PROTECTED](804)684-7900w [EMAIL PROTECTED] (804)642-0662h http://maplepark.com/~drf5n/ __ R-help@stat.math.ethz.ch 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.
Re: [R] search path question
Thanks, Barry.
In fact, I have a function just like yours, and I'm looking for a simple
alternative function, which is like path in Matlab.
On 5/29/07, Barry Rowlingson [EMAIL PROTECTED] wrote:
Zhiliang Ma wrote:
I want to find a function that can simply add
C:\inFiles\ into R's search path, so that we I scan a file R will go
to
all the search paths to find it. In matlab, path(path,C:\inFiles) will
do
this job, I'm just wondering if there is a similar function in R can do
this
job.
Something like this (not extensively tested):
`sscan` -
function(name, path=options()$scanpath,...){
for(p in path){
file=file.path(p,name)
if(file.exists(file)){
return(scan(file,...))
}
## last resort..
return(scan(name,...))
}
}
Then do:
options(scanpath=/tmp)
and then:
sscan(foo.data)
will look for /tmp/foo.data first, then if that fails it will do the
'last resort' which is to look in the current directory.
My worry is that this will bite you one day - if you have two files
with the same name, it will get the first one in your scanpath - one day
this will not be the one you think it is
Note this only works with 'scan' - you'll have to do the same thing
for read.table, source, etc etc if you want them to behave with a search
path too. Unless there's a lower-level approach. But that really will
bite you!
Barry
Barry
[[alternative HTML version deleted]]
__
R-help@stat.math.ethz.ch 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.
Re: [R] search path question
Zhiliang Ma wrote: Thanks, Barry. In fact, I have a function just like yours, and I'm looking for a simple alternative function, which is like path in Matlab. Dont think it can be done - if you look at the code for 'scan', it disappears off into internal() calls to do the business of finding and reading a file, so you're going to have trouble changing its behaviour in R. You'd have to patch R's C source to implement a search path. Barry __ R-help@stat.math.ethz.ch 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.
Re: [R] search path question
Actually, it does
if (is.character(file))
if (file == )
file - stdin()
else {
file - file(file, r)
on.exit(close(file))
}
so all the searching is done in the file() connection.
You could do this via a search_file() connection wrapper, but there is a
problem with ensuring connections get closed (which on.exit does here).
On Tue, 29 May 2007, Barry Rowlingson wrote:
Zhiliang Ma wrote:
Thanks, Barry.
In fact, I have a function just like yours, and I'm looking for a simple
alternative function, which is like path in Matlab.
Dont think it can be done - if you look at the code for 'scan', it
disappears off into internal() calls to do the business of finding and
reading a file, so you're going to have trouble changing its behaviour
in R. You'd have to patch R's C source to implement a search path.
Barry
__
R-help@stat.math.ethz.ch 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.
--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UKFax: +44 1865 272595
__
R-help@stat.math.ethz.ch 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.
