[R] Comparing figures?

[Martin Maechler]

>>>>> Suzen, Mehmet <mehmet.suzen using gmail.com>
>>>>>     on Mon, 7 May 2018 15:48:57 +0000 writes:

    > I suggest perceptual diff. You could write a wrapper
    > around it.  http://pdiff.sourceforge.net

In (base) R's own test ('make check-devel'), we basically use

   pdf(*, compress=FALSE)

actually also setting 'encoding=.' and 'paper=.', see the R sources at
   https://svn.r-project.org/R/trunk/tests/reg-plot.R

and the check (source at
    https://svn.r-project.org/R/trunk/tests/Makefile.common)

basically is using

    R CMD Rdiff  <foo>.pdf  <foo>.pdf.save

(with <foo> := reg-plot in this case)

Martin Maechler
R Core Team


    > On Mon, 7 May 2018 16:49 Ramiro Barrantes,
    > <ramiro using precisionbioassay.com> wrote:

    >> Hello,
    >> 
    >> I am working on tests to compare figures.  I have been
    >> using ImageMagick, which creates a figure signature, and
    >> I can compare a "test" figure signature against a saved
    >> "reference" figure signature.  It seems to work pretty
    >> well.  However, it is slow as it requires reading from
    >> the file system.
    >> 
    >> Are there any options to compare figures on memory?  For
    >> example, if I generate a ggplot or lattice graph, I could
    >> have all my saved "reference" figures on memory (which I
    >> would have loaded all at once) and compare them.  I just
    >> haven't found anything.
    >> 
    >> I just found out about the vdiffr package and was going
    >> to explore it, not sure about the speed.
    >> 
    >> Any suggestions appreciated.
    >> 
    >> Thank you, <
    >> https://west.exch023.serverdata.net/owa/?ae=Item&a=New&t=IPM.Note&cc=MTQuMy4zMTkuMixlbi1VUyw2LEhUTUwsMCww&pspid=_1525698150389_875737489#
    >> >
    >> Ramiro
    >> 
    >> Ramiro Barrantes Ph.D.  Precision Bioassay, Inc.  431
    >> Pine St., Suite 110 Burlington, VT 05401 802 865 0155 802
    >> 861 2365 FAX www.precisionbioassay.com<
    >> https://west.exch023.serverdata.net/owa/redir.aspx?SURL=wN3KzpoKXAcetH7sTOTnSyfg-iAXFIinpPUtRcduCFCtkgZrUSDTCGgAdAB0AHAAOgAvAC8AdwB3AHcALgBwAHIAZQBjAGkAcwBpAG8AbgBiAGkAbwBhAHMAcwBhAHkALgBjAG8AbQA.&URL=http%3a%2f%2fwww.precisionbioassay.com
    >> >
    >> ramiro using precisionbioassay.com
    >> 
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    > ______________________________________________
    > R-help using r-project.org mailing list -- To UNSUBSCRIBE and
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    > PLEASE do read the posting guide
    > http://www.R-project.org/posting-guide.html and provide
    > commented, minimal, self-contained, reproducible code.