[R] Reading data

[Henrik Bengtsson]

On Fri, Sep 25, 2009 at 10:18 AM, Henrik Bengtsson <hb at stat.berkeley.edu> wrote:
> You can use R.utils (on CRAN) to help you figure out why the file is
> not found or not readable.
>
> library("R.utils");
> pathname <- C:/Documents and Settings/ashta/My Documents/R_data/rel.dat";
> pathname <- Arguments$getReadablePathname(pathname);
> rel <- read.table(pathname, quote="", header=FALSE, sep="",
> col.names=c("id","orel","nrel"));
>
> If the file is not found it gives an error an tries to tell you why, e.g.
>
>> Arguments$getReadablePathname("C:/Windows/system32/cmd.exe")
> [1] "C:/Windows/system32/cmd.exe"
>
>> Arguments$getReadablePathname("C:/Windows/system323/cmd.exe")
> Error in list(`Arguments$getReadablePathname("C:/Windows/system323/cmd.exe")` =
> <environment>,  :
>
> [2009-09-25 10:11:57] Exception: Pathname not found:
> C:/Windows/system323/cmd.exe (C:/Windows/ exists, but nothing beyond)
>  at throw(Exception(...))
>  at throw.default("Pathname not found: ", pathname, reason)
>  at throw("Pathname not found: ", pathname, reason)
>  at method(static, ...)
>  at Arguments$getReadablePathname("C:/Windows/system323/cmd.exe")
>
> It will also tell you if the file exists, but you don't have the
> permission to read it.
>
>
> Second, your error message reports on a pathname that starts with
> 'file=', which I've never seen;
>
>  cannot open file 'file=C:/Documents and
> Settings/sewalem/MyDocuments/R_data/rel.dat': Invalid argument
>
> what version of R are you use, i.e. what does sessionInfo() give?

Did you *really* do?

 rel <- read.table("C:/Documents and
Settings/sewalem/MyDocuments/R_data/rel.dat", quote="", header=FALSE,
sep="", col.names=c("id","orel","nrel"))

or did you try to do:

 rel <- read.table(file="C:/Documents and
Settings/sewalem/MyDocuments/R_data/rel.dat", quote="", header=FALSE,
sep="", col.names=c("id","orel","nrel"))

but wrote?

 rel <- read.table("file=C:/Documents and
Settings/sewalem/MyDocuments/R_data/rel.dat", quote="", header=FALSE,
sep="", col.names=c("id","orel","nrel"))

/H

>
>
> Third, it is true that backslashes need to be escaped.  However,
> *forward-slashes* work with *any
> platform*.  I stick with the latter so I don't have to think about it.
>  It should make no difference in your case.
>
>
> My $.02
>
> /Henrik
>
> On Fri, Sep 25, 2009 at 7:32 AM, Michael A. Miller <mmiller3 at iupui.edu> wrote:
>> Sometimes it is easiest to open a file using a file selection
>> widget.  I keep this in my .Rprofile:
>>
>> getOpenFile <- function(...){
>>  require(tcltk)
>>  return(tclvalue(tkgetOpenFile()))
>> }
>>
>> With this you can find your file and open it with
>>
>>  rel <- read.table(getOpenFile(), quote="", header=FALSE, sep="", col.names=c("id","orel","nrel"))
>>
>> or
>>
>>  filename <- getOpenFile()
>>  rel <- read.table(filename, quote="", header=FALSE, sep="", col.names=c("id","orel","nrel"))
>>
>> Mike
>>
>>
>> P.S. I keep a couple functions on hand for choosing writable files
>> and directories too...
>>
>> getSaveFile <- function(...){
>>  require(tcltk)
>>  return(tclvalue(tkgetSaveFile()))
>> }
>>
>> chooseDir <- function(...){
>>  require(tcltk)
>>  return(tclvalue(tkchooseDirectory()))
>> }
>>
>> ______________________________________________
>> R-help at r-project.org 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.
>>
>