R help - Feb 2004 - How to detect whether a file exists or not?

I would like my program to load variables x,y,x from a file 'myFile.r'
but
if this file does not exist, I want my program to create/initialize x,y,z.

Does anyone know how to do this?

Thank you very much.

Francisco J. Molina

On Wed, Feb 11, 2004 at 07:22:00PM -0800, Francisco J Molina
wrote:
> 
> I would like my program to load variables x,y,x from a file
'myFile.r' but
> if this file does not exist, I want my program to create/initialize x,y,z.
> 
> Does anyone know how to do this?
?file.info			# as help.search("file") would have revealed

Hth, Dirk

-- 
The relationship between the computed price and reality is as yet unknown.  
                                             -- From the pac(8) manual page

You can adapt this to your situation:

   z <- try( read.table("myfile", header=T) )
   if (class(z) == "try-error") z <- data.frame(x=1,y=2,z=3)

You may also be interested in the silent= arg of try.  See ?try

Date:   Wed, 11 Feb 2004 19:22:00 -0800 
From:   Francisco J Molina <fjmolina at ams.ucsc.edu>
To:   r-help <r-help at stat.math.ethz.ch> 
Subject:   [R] How to detect whether a file exists or not? 

 

I would like my program to load variables x,y,x from a file 'myFile.r'
but
if this file does not exist, I want my program to create/initialize x,y,z.

Does anyone know how to do this?

Thank you very much.

Francisco J. Molina

> I would like my program to load variables x,y,x from a file
'myFile.r' but
> if this file does not exist, I want my program to create/initialize x,y,z.
> Does anyone know how to do this?
?file.exists