R devel - Aug 2012 - Compressing data for package builds

Hi,

 I have two  .rda files that I need to include in a package.  I've placed
them both in a data directory
 after  save()  the are around  150Kb  each.

When I try to check the package I get the following warning

Warning: large data file(s) saved inefficiently:
                size ASCII compress
  zagoskin.rda 137Kb FALSE     none

  Note: significantly better compression could be obtained
        by using R CMD build --resave-data
               old_size new_size compress
  modpoll.rda     124Kb     78Kb       xz
  zagoskin.rda    137Kb      6Kb    bzip2

Both of these files modpoll.rda and zagoskin.rda  have already been
compressed from megabytes down to Kb.

Also,, the  instructions    "R CMD build --resave-data"  doesnt do
anything
that I can see so I must be using it wrong.
Is there a piece of the puzzle I am missing or instructions better than
these: I tried  LazyDataCompression and my
data.rdb is 90Kb.

"Package *tools* has a couple of functions to help with data images:
checkRdaFiles reports on the way the image was saved, and resaveRdaFiles will
re-save with a different type of compression, including choosing the best
type for that particular image.

Some packages using ‘LazyData’ will benefit from using a form of
compression other than gzip in the installed lazy-loading database. This
can be selected by the --data-compress option to R CMD INSTALL or by using
the ‘LazyDataCompression’ field in the DESCRIPTION file. Useful values are
bzip2, xz and the default, gzip. The only way to discover which is best is
to try them all and look at the size of the pkgname/data/Rdata.rdb file."

	[[alternative HTML version deleted]]

On Aug 16, 2012, at 5:08 PM, steven mosher wrote:
> Hi,
> 
> I have two  .rda files that I need to include in a package.  I've
placed
> them both in a data directory
> after  save()  the are around  150Kb  each.
> 
> When I try to check the package I get the following warning
> 
> Warning: large data file(s) saved inefficiently:
>                size ASCII compress
>  zagoskin.rda 137Kb FALSE     none
> 
>  Note: significantly better compression could be obtained
>        by using R CMD build --resave-data
>               old_size new_size compress
>  modpoll.rda     124Kb     78Kb       xz
>  zagoskin.rda    137Kb      6Kb    bzip2
> 
> Both of these files modpoll.rda and zagoskin.rda  have already been
> compressed from megabytes down to Kb.
> 
> Also,, the  instructions    "R CMD build --resave-data"  doesnt
do anything
> that I can see so I must be using it wrong.
R CMD build is how you preferably should be creating your package tar ball, so
you simply add the --resave-data argument to your already existing R CMD build
call which creates the tar ball from your source directory. So can you elaborate
on "doesn't do anything I can see"? In what sense? No output? No
compression?

Cheers,
Simon

> Is there a piece of the puzzle I am missing or instructions better than
> these: I tried  LazyDataCompression and my
> data.rdb is 90Kb.
> 
> "Package *tools* has a couple of functions to help with data images:
> checkRdaFiles reports on the way the image was saved, and resaveRdaFiles
will
> re-save with a different type of compression, including choosing the best
> type for that particular image.
> 
> Some packages using ?LazyData? will benefit from using a form of
> compression other than gzip in the installed lazy-loading database. This
> can be selected by the --data-compress option to R CMD INSTALL or by using
> the ?LazyDataCompression? field in the DESCRIPTION file. Useful values are
> bzip2, xz and the default, gzip. The only way to discover which is best is
> to try them all and look at the size of the pkgname/data/Rdata.rdb
file."
> 
> 	[[alternative HTML version deleted]]
> 
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