R devel - Aug 2002 - bug in garbage collector function gc() documentation (PR#1970)

Full_Name: Saket Joshi
Version: 1.5.0
OS: Solaris 5.8
Submission from: (NULL) (128.193.38.91)


According to the documentation obtained by entering:
help.search("gc"), the
command gc() forces garbage collection and gives the memory usage statistics
along with the trigger values in bytes also interpretted in megabytes. However
when I ran gc(), the result was a list giving the memory usage in bytes and
interpretted in Megabits and not mega bytes.

e.g.
> gc()
	   used  (Mb) gc trigger  (Mb)
Ncells   288733   7.8     818163  21.9
Vcells 30158416 230.1   48892294 373.1

As can be seen, 230.1 is the interpretation of 30158416 bytes as megabits. But
the documentation says megabytes.
 


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The help page is correct: please read it more carefully:

     `gc' returns a matrix with rows `"Ncells"' (cons cells,
usually 28
     bytes each on 32-bit systems and 56 bytes on 64-bit systems, and
     `"Vcells"' (vector cells, 8 bytes each), and columns
`"used"' and
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
    `"gc trigger"', each also interpreted in megabytes (rounded up
to
     the next 0.1Mb).

`30158416 bytes' is your invention: gc() actually reports `30158416
Vcells'.


On Sat, 31 Aug 2002 joshi@engr.orst.edu wrote:
> Full_Name: Saket Joshi
> Version: 1.5.0
> OS: Solaris 5.8
> Submission from: (NULL) (128.193.38.91)
>
>
> According to the documentation obtained by entering:
help.search("gc"), the
> command gc() forces garbage collection and gives the memory usage
statistics
> along with the trigger values in bytes also interpretted in megabytes.
However
> when I ran gc(), the result was a list giving the memory usage in bytes and
> interpretted in Megabits and not mega bytes.
It *is* matrix as stated, and not a list!
> e.g.
>
> > gc()
>
> 	   used  (Mb) gc trigger  (Mb)
> Ncells   288733   7.8     818163  21.9
> Vcells 30158416 230.1   48892294 373.1
>
> As can be seen, 230.1 is the interpretation of 30158416 bytes as megabits.
But
> the documentation says megabytes.

-- 
Brian D. Ripley,                  ripley@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 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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