readJPEG function cannot open jpeg files

Similar issue with URLs:
Not a similar issue at all: a URL is not a file.  That most functions in 
R itself open connections including URLs does not mean that contributed 
packages do.  The package help is quite specific about its requirements.

   source: Either name of the file to read from or a raw vector
           representing the JPEG file content.

Which suggests to you how you can do this, apart from download.file, of 
course.  Something like

readJPEG(readBin(yesWeCan, "raw", 1e6))

yesWeCan <- "http://upload.wikimedia.org/wikipedia/commons/9/9d/Barack_Obama.jpg"
url(yesWeCan)
                                                           description
"http://upload.wikimedia.org/wikipedia/commons/9/9d/Barack_Obama.jpg"
                                                                 class
                                                                 "url"
                                                                  mode
                                                                   "r"
                                                                  text
                                                                "text"
                                                                opened
                                                              "closed"
                                                              can read
                                                                 "yes"
                                                             can write
                                                                  "no"
readJPEG(yesWeCan)
Error in readJPEG(yesWeCan) :
   unable to open
http://upload.wikimedia.org/wikipedia/commons/9/9d/Barack_Obama.jpg

On 14 January 2013 14:57, 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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Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
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readJPEG function cannot open jpeg files

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