[R] saveRDS() and readRDS() Why?

[Patrick Connolly]

On Wed, 07-Nov-2018 at 08:27AM +0000, Robert David Burbidge wrote:

|> Hi Patrick,
|> 
|> From the help: "save writes a single line header (typically
|> "RDXs\n") before the serialization of a single object".
|> 
|> If the file sizes are the same (see Eric's message), then the
|> problem may be due to different line terminators. Try serialize and
|> unserialize for low-level control of saving/reading objects.

I'll have to find out what 'serialize' means.

On Windows, it's a huge table, looks like it's all hexadecimal.  

On Linux, it's just the text string 'rawData' -- a lot more than line
terminators.

Have I misunderstood what the idea is?  I thought I'd get an identical
object, irrespective of how different the OS stores and zips it.



|> 
|> Rgds,
|> 
|> Robert
|> 
|> 
|> On 07/11/18 08:13, Eric Berger wrote:
|> >What do you see at the OS level?
|> >i.e. on windows
|> >DIR rawData.rds
|> >on linux
|> >ls -l rawData.rds
|> >compare the file sizes on both.
|> >
|> >
|> >On Wed, Nov 7, 2018 at 9:56 AM Patrick Connolly <p_connolly using slingshot.co.nz>
|> >wrote:
|> >
|> >> From a Windows R session, I do
|> >>
|> >>>object.size(rawData)
|> >>31736 bytes  # from scraping a non-reproducible web address.
|> >>>saveRDS(rawData, file = "rawData.rds")
|> >>Then copy to a Linux session
|> >>
|> >>>rawData <- readRDS(file = "rawData.rds")
|> >>>rawData
|> >>[1] "rawData"
|> >>>object.size(rawData)
|> >>112 bytes
|> >>>rawData
|> >>[1] "rawData" # only the name and something to make up 112 bytes
|> >>Have I misunderstood the syntax?
|> >>
|> >>It's an old version on Windows.  I haven't used Windows R since then.
|> >>
|> >>major          3
|> >>minor          2.4
|> >>year           2016
|> >>month          03
|> >>day            16
|> >>
|> >>
|> >>I've tried R-3.5.0 and R-3.5.1 Linux versions.
|> >>
|> >>In case it's material ...
|> >>
|> >>I couldn't get the scraping to work on either of the R installations
|> >>but Windows users told me it worked for them.  So I thought I'd get
|> >>the R object and use it.  I could understand accessing the web address
|> >>could have different permissions for different OSes, but should that
|> >>affect the R objects?
|> >>
|> >>TIA
|> >>
|> >>--
|> >>~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.
|> >>    ___    Patrick Connolly
|> >>  {~._.~}                   Great minds discuss ideas
|> >>  _( Y )_                 Average minds discuss events
|> >>(:_~*~_:)                  Small minds discuss people
|> >>  (_)-(_)                              ..... Eleanor Roosevelt
|> >>
|> >>~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.
|> >>
|> >>______________________________________________
|> >>R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
|> >>https://stat.ethz.ch/mailman/listinfo/r-help
|> >>PLEASE do read the posting guide
|> >>http://www.R-project.org/posting-guide.html
|> >>and provide commented, minimal, self-contained, reproducible code.
|> >>
|> >	[[alternative HTML version deleted]]
|> >
|> >______________________________________________
|> >R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
|> >https://stat.ethz.ch/mailman/listinfo/r-help
|> >PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
|> >and provide commented, minimal, self-contained, reproducible code.

-- 
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.   
   ___    Patrick Connolly   
 {~._.~}                   Great minds discuss ideas    
 _( Y )_  	         Average minds discuss events 
(:_~*~_:)                  Small minds discuss people  
 (_)-(_)  	                      ..... Eleanor Roosevelt
	  
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.