R help - Mar 2015 - error message: ReadItem: unknown type 64, perhaps written by later version of R

Dear all

I get the following error message when I try to load one  specific RData object
in R:

        Error: ReadItem: unknown type 64, perhaps written by later version of R


The error message is odd because (a) this RData object was created just one hour
berfore in a  previous script (in a series of R scripts called in batch mode),
so it would seem to me that it has been created by the same version of R that is
now calling it (b) this script is "looping" over several scenarios and
years, and the error only occurs for one very specific combination of scenarios
and years. This object is about 6 Gb large, which is the same  size as the other
objects that were called in previous instances.

I load the RData with the following command (where pathsony[[rdata]] is the
folder with the RData and skimlistrdata is the file I try to load):

        load( file.path(pathsony[[rdata]],skimlistrdata))


The problem occurs both when I run the script in batch mode or when I run it
interactively.

I use a  "x86_64-pc-linux-gnu" and  "R version 3.1.2
(2014-10-31)".


Laurent Franckx, PhD
Senior researcher sustainable mobility
VITO NV | Boeretang 200 | 2400 Mol
Tel. ++ 32 14 33 58 22| mob. +32 479 25 59 07 | Skype: laurent.franckx |
laurent.franckx at vito.be | Twitter @LaurentFranckx




VITO Disclaimer: http://www.vito.be/e-maildisclaimer

On 05/03/2015 20:34, Franckx Laurent wrote:
> Dear all
>
> I get the following error message when I try to load one  specific RData
object in R:
>
>          Error: ReadItem: unknown type 64, perhaps written by later version
of R
>
>
> The error message is odd because (a) this RData object was created just one
hour berfore in a  previous script (in a series of R scripts called in batch
mode), so it would seem to me that it has been created by the same version of R
that is now calling it (b) this script is "looping" over several
scenarios and years, and the error only occurs for one very specific combination
of scenarios and years. This object is about 6 Gb large, which is the same  size
as the other objects that were called in previous instances.
What is 'odd' is that you missed the 'perhaps'.

The most likely explanation is an I/O error when the file was written: 
it is 'perhaps' corrupted.

> I load the RData with the following command (where pathsony[[rdata]] is the
folder with the RData and skimlistrdata is the file I try to load):
>
>          load( file.path(pathsony[[rdata]],skimlistrdata))
>
>
> The problem occurs both when I run the script in batch mode or when I run
it interactively.
>
> I use a  "x86_64-pc-linux-gnu" and  "R version 3.1.2
(2014-10-31)".
>
>
> Laurent Franckx, PhD
> Senior researcher sustainable mobility
> VITO NV | Boeretang 200 | 2400 Mol
> Tel. ++ 32 14 33 58 22| mob. +32 479 25 59 07 | Skype: laurent.franckx |
laurent.franckx at vito.be | Twitter @LaurentFranckx

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Emeritus Professor of Applied Statistics, University of Oxford
1 South Parks Road, Oxford OX1 3TG, UK

> -----Original Message-----
> From: Prof Brian Ripley [mailto:ripley at stats.ox.ac.uk]
> Sent: vrijdag 6 maart 2015 10:23
> To: Franckx Laurent; r-help at r-project.org
> Subject: Re: [R] error message: ReadItem: unknown type 64, perhaps written
> by later version of R
>
> On 05/03/2015 20:34, Franckx Laurent wrote:
> > Dear all
> >
> > I get the following error message when I try to load one  specific
RData
> object in R:
> >
> >          Error: ReadItem: unknown type 64, perhaps written by later
> > version of R
> >
> >
> > The error message is odd because (a) this RData object was created
just
> one hour berfore in a  previous script (in a series of R scripts called in
batch
> mode), so it would seem to me that it has been created by the same version
> of R that is now calling it (b) this script is "looping" over
several scenarios and
> years, and the error only occurs for one very specific combination of
> scenarios and years. This object is about 6 Gb large, which is the same 
size as
> the other objects that were called in previous instances.
>
> What is 'odd' is that you missed the 'perhaps'.
>
> The most likely explanation is an I/O error when the file was written:
> it is 'perhaps' corrupted.
>
>
Dear Professor Riply,

Thank you for your suggestion.

The possibility of an I/O error in the writing of the file is actually something
I had anticipated. The saving of the file is immediately followed by a test -
see the code below.

        save(list = skimlistname, file =
file.path(pathsony[[rdata]],skimlistnamerdata))
        if(file.exists(file.path(pathsony[[rdata]],skimlistnamerdata))) {
                cat(skimlistnamerdata, " has been created. \n ", file
= warningfile, sep = "", append = TRUE)
                } else {
                stop(skimlistnamerdata, " has not been created correctly.
\n ")
                }

My understanding was that this test code would stop the execution of the program
if the file had not been saved correctly.
Moreover, each of my script starts with a verification whether any error message
is contained in the Rout of the preceding scripts, and stops execution
immediately if this is indeed the case.
Therefore, I should not even have reached the point where R tries to load the
file in memory.
Is there any alternative to verifying whether a file has been created correctly
without actually loading it?
Sincerely,
Laurent Franckx


> > I load the RData with the following command (where pathsony[[rdata]]
is
> the folder with the RData and skimlistrdata is the file I try to load):
> >
> >          load( file.path(pathsony[[rdata]],skimlistrdata))
> >
> >
> > The problem occurs both when I run the script in batch mode or when I
run
> it interactively.
> >
> > I use a  "x86_64-pc-linux-gnu" and  "R version 3.1.2
(2014-10-31)".
> >
> >
> > Laurent Franckx, PhD
> > Senior researcher sustainable mobility VITO NV | Boeretang 200 | 2400
> > Mol Tel. ++ 32 14 33 58 22| mob. +32 479 25 59 07 | Skype:
> > laurent.franckx | laurent.franckx at vito.be | Twitter @LaurentFranckx
>
>
> --
> Brian D. Ripley,                  ripley at stats.ox.ac.uk
> Emeritus Professor of Applied Statistics, University of Oxford
> 1 South Parks Road, Oxford OX1 3TG, UK
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