[R] readJPEG function cannot open jpeg files
Duncan Murdoch
murdoch.duncan at gmail.com
Mon Jan 14 20:04:46 CET 2013
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 the
Explorer options to display full filenames. That would have prevented
this error. (This is an option in Windows, not in R.)
I've never understood why Microsoft thinks it is good to display
incomplete filenames. This practice causes so many problems.
Duncan Murdoch
>
>
> On Mon, Jan 14, 2013 at 11:59 AM, Yi Yuan <lambandme at 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 <wdunlap at 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-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...
>>>> 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 <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.
>>>>>
>>>>> [[alternative HTML version deleted]]
>>>>>
>>>>> ______________________________________________
>>>>> 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.
>>>>
>>>> ______________________________________________
>>>> 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.
>>>
>>
>>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
>
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