[R] extracting a R object from an R image

[Martin Maechler]

>>>>> Jeff Newmiller 
>>>>>     on Fri, 05 Nov 2021 16:45:02 -0700 writes:

    > IMO you are being a bit too literal. It is absolutely possible to load the file into a dedicated environment and use the $ or [[]] extraction operator to access a specific object in that environment.
    > ?load
    > ?new.env

    > Or, you can attach the file, copy to a new variable, and detach. (see examples in ?load)

Exactly: In the eyes of most R experts, it is the only useful use of attach():

   attach(".RData") 
   ls.str(2) # -> get alevel-1 str(.) of the objects in your image


    > On November 5, 2021 3:26:49 PM PDT, Bert Gunter <bgunter.4567 using gmail.com> wrote:
    >> You can't. You can only save and load whole .RData files. You can, of
    >> course, save and load separate R objects in separate files. But note
    >> in ?save.image:
    >> 
    >> "For saving single R objects, saveRDS() is mostly preferable to
    >> save(), notably because of the functional nature of readRDS(), as
    >> opposed to load(). "
    >> 
    >> You may wish to search on "data serialization" (e.g. on Wikipedia) or
    >> similar to better understand the underlying ideas.
    >> 
    >> Bert Gunter
    >> 
    >> "The trouble with having an open mind is that people keep coming along
    >> and sticking things into it."
    >> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
    >> 
    >> Bert Gunter
    >> 
    >> "The trouble with having an open mind is that people keep coming along
    >> and sticking things into it."
    >> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
    >> 
    >> 
    >> On Fri, Nov 5, 2021 at 3:01 PM Bogdan Tanasa <tanasa using gmail.com> wrote:
    >>> 
    >>> Dear all,
    >>> 
    >>> I saved my work in a Rimage that contains multiple objects ;
    >>> 
    >>> the objects were generated with Monocle3 :
    >>> 
    >>> https://cole-trapnell-lab.github.io/monocle3/docs/starting/
    >>> 
    >>> one object is called CDS.
    >>> 
    >>> How shall I extract this object CDS (that has a complex structure) from the
    >>> R image ?
    >>> 
    >>> thank you,
    >>> 
    >>> Bogdan
    >>> 
    >>> [[alternative HTML version deleted]]
    >>> 
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    >>> and provide commented, minimal, self-contained, reproducible code.
    >> 
    >> ______________________________________________
    >> 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.

    > -- 
    > Sent from my phone. Please excuse my brevity.

    > ______________________________________________
    > 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.