From hadley at rice.edu  Tue Feb  8 00:15:46 2011
From: hadley at rice.edu (Hadley Wickham)
Date: Mon, 7 Feb 2011 17:15:46 -0600
Subject: [Rd] Save and serialize
In-Reply-To: <AANLkTik4_6mxWQDEwicx9-k+CnYTDkYMaLs-rN-wdG8F@mail.gmail.com>
References: <AANLkTimQe8suNsPmVryHfNZp1YLFk=RYenFfvn9bh24_@mail.gmail.com>
	<alpine.LFD.2.02.1102072144470.25585@gannet.stats.ox.ac.uk>
	<AANLkTik4_6mxWQDEwicx9-k+CnYTDkYMaLs-rN-wdG8F@mail.gmail.com>
Message-ID: <AANLkTimQQPzHnrxtLBS2V3xVMnLmsaJ2tKj0_ZN4pfaP@mail.gmail.com>

Thanks to you both for the information - that's exactly the level of
detail I was looking for.  I ask because I want to play around with a
function to automatically cache expensive operations to disk, in a way
that can be lazy loaded on the next run.

Hadley

On Mon, Feb 7, 2011 at 4:06 PM, Henrik Bengtsson <hb at biostat.ucsf.edu> wrote:
> Also, if it it adds any value to what you are looking for, the output
> of serialize() also has header information, cf. R-devel thread 'Small
> inconsistency in serialize() between R versions and ? ? implications on
> digest()' started March 7, 2007:
>
> ?http://www.mail-archive.com/r-devel at r-project.org/msg07931.html
>
> It caused us some headaches when trying to generate identical output
> of the same input using different versions of R. ?It was solved in
> that thread. ?See code for digest::digest() on how to skip/ignore that
> header.
>
> /Henrik
>
>
> On Mon, Feb 7, 2011 at 1:51 PM, Prof Brian Ripley <ripley at stats.ox.ac.uk> wrote:
>> On Mon, 7 Feb 2011, Hadley Wickham wrote:
>>
>>> Hi all,
>>>
>>> Is there any relationship between save and serialize? ?Do they use the
>>> same algorithm?
>>
>> See the R-internals manual: there is more info in the R-devel version, not
>> least because saveRDS() is added to the mix.
>>
>> But basically serialize() and saveRDS() use the same format, and save()
>> writes a header and then serializes a pairlist of the objects given.
>>
>> 'The same algorithm' is somewhat misleading here: strictly no, as they
>> manage to use four entry points to the code base.
>>
>>>
>>> Hadley
>>>
>>> --
>>> Assistant Professor / Dobelman Family Junior Chair
>>> Department of Statistics / Rice University
>>> http://had.co.nz/
>>>
>>> ______________________________________________
>>> R-devel at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>>
>>
>> --
>> Brian D. Ripley, ? ? ? ? ? ? ? ? ?ripley at stats.ox.ac.uk
>> Professor of Applied Statistics, ?http://www.stats.ox.ac.uk/~ripley/
>> University of Oxford, ? ? ? ? ? ? Tel: ?+44 1865 272861 (self)
>> 1 South Parks Road, ? ? ? ? ? ? ? ? ? ? +44 1865 272866 (PA)
>> Oxford OX1 3TG, UK ? ? ? ? ? ? ? ?Fax: ?+44 1865 272595
>>
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>
>



-- 
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/



[Rd] Save and serialize
Hadley Wickham