readJPEG function cannot open jpeg files

You can use file.info("myFile") to make sure the file exists and has appropriate permissions ("mode"
in file.info's lingo, as in Unix).  E.g.,
file.info("c:/temp/BO.jpeg") # this one does not exist
size isdir mode mtime ctime atime  exe
c:/temp/BO.jpeg   NA    NA <NA>  <NA>  <NA>  <NA> <NA>
file.info("c:/temp/BO.jpg") # this one exists
size isdir mode               mtime               ctime               atime
c:/temp/BO.jpg 150536 FALSE  666 2013-01-14 08:35:32 2013-01-14 08:33:09 2013-01-14 08:33:09
               exe
c:/temp/BO.jpg  no

I can readJPEG() the file with mode 666, but not all permission information is encoded in the mode. 

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf
Of Jeff Newmiller
Sent: Monday, January 14, 2013 8:25 AM
To: Yi Yuan; r-help at r-project.org
Subject: Re: [R] readJPEG function cannot open jpeg files

Being unable to open a file is a related to your operating system and how R interacts with
that OS. If your interactive development environment (IDE, of which RStudio is an
example) is trying to make things simpler for you but you don't understand how to use it,
then you need to ask help from your RStudio support resources, not here.

When posting here, you should mention your results from using base R functions like

?sessionInfo
?getwd
?list.files

as indicated in the Posting Guide mentioned at the bottom of every R-help email.

Consistent with the fact that this is an interface issue between R and the OS, sometimes
you will have to investigate the problem from outside R. For example, you might need to
investigate issues with security permissions that are OS specific and completely outside
the scope of this forum.
---------------------------------------------------------------------------
Jeff Newmiller                        The     .....       .....  Go Live...
DCN:<jdnewmil at dcn.davis.ca.us>        Basics: ##.#.       ##.#.  Live Go...
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Research Engineer (Solar/Batteries            O.O#.       #.O#.  with
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Sent from my phone. Please excuse my brevity.

Yi Yuan <lambandme at gmail.com> wrote:

I installed jpeg package and tried to use

kim<-readJPEG("kim.jpeg") to read in a jpeg file, but R gave me an
error:
Error in readJPEG("kim.jpeg") : unable to open kim.jpeg

I already put "kim.jpeg" in Rstudio's default working directory:
"E:\home
work\Rstudio". So I don't think it's a problem caused by omitting the
file's
path. But I tried with the full path version just in case and still got
the
"unable to open" error:

kim<-readJPEG("E:\\ home work\\Rstudio\\kim.jpeg")
Error in readJPEG("E:\\ home work\\Rstudio\\kim.jpeg") :
 unable to open E:\ home work\Rstudio\kim.jpeg

So now I really don't know what is wrong.

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and provide commented, minimal, self-contained, reproducible code.

readJPEG function cannot open jpeg files

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