Re: [R] readJPEG function cannot open jpeg files

Duncan Murdoch Mon, 14 Jan 2013 11:08:34 -0800

On 13-01-14 12:18 PM, Yi Yuan wrote:

Hi, guys, my problem is solved.
I used file.info(list.files(getwd(),full.names=TRUE)) and found out that
the said file is listed as "kim.jpg" instead of "kim.jpeg". So
kim<-readJPEG("kim.jpg") worked. Thanks for your help and sorry for my
newbie question.

Another recommendation I make for all Windows users is to change theExplorer options to display full filenames. That would have preventedthis error. (This is an option in Windows, not in R.)

I've never understood why Microsoft thinks it is good to displayincomplete filenames. This practice causes so many problems.


Duncan Murdoch



On Mon, Jan 14, 2013 at 11:59 AM, Yi Yuan <lamban...@gmail.com> wrote:

Thanks William !

  file.info("E:/ home work/Rstudio/kim.jpeg")
                                        size isdir mode mtime ctime atime
  exe
E:/home work/Rstudio/kim.jpeg   NA    NA <NA>  <NA>  <NA>  <NA> <NA>

So R thinks this file doesn't exist? But the file is already in "E:/ home
work/Rstudio" folder, I don't understand why file.info( ) returned such
message. I have multiple files in this directory "E:/home work/Rstudio",
but R shows:
file.info("E:/home work/Rstudio")
                                          size isdir mode
mtime               ctime               atime exe
E:/home work/Rstudio    0  TRUE  777 2013-01-13 22:12:58 2013-01-13
20:57:36 2013-01-13 22:12:58  no

  Any help ?

On Mon, Jan 14, 2013 at 11:44 AM, William Dunlap <wdun...@tibco.com>wrote:

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-boun...@r-project.org [mailto:r-help-boun...@r-project.org]

On Behalf

Of Jeff Newmiller
Sent: Monday, January 14, 2013 8:25 AM
To: Yi Yuan; r-help@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:<jdnew...@dcn.davis.ca.us>        Basics: ##.#.       ##.#.  Live

Go...

                                       Live:   OO#.. Dead: OO#..  Playing
Research Engineer (Solar/Batteries            O.O#.       #.O#.  with
/Software/Embedded Controllers)               .OO#.       .OO#.

  rocks...1k

---------------------------------------------------------------------------

Sent from my phone. Please excuse my brevity.

Yi Yuan <lamban...@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.

     [[alternative HTML version deleted]]

______________________________________________
R-help@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.


______________________________________________
R-help@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.


        [[alternative HTML version deleted]]

______________________________________________
R-help@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.


______________________________________________
R-help@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.

Re: [R] readJPEG function cannot open jpeg files

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