R help - Mar 2007 - memory, speed, and assigning results into new v. existing variable

I have a very large data frame, and I'm doing a conversion of all columns
into factors. Takes a while (thanks to folks here though, for making
faster!), but am wondering about optimization from a memory perspective...

Internally, am I better off assigning into a new data frame, or doing one of
these:

dataframe<-someoperation(dataframe)

It would seem that re-assigning into the same data frame *might* be more
efficient in that I don't have to double the memory with 2 objects, but then
again.. there'd have to be a "working copy" in memory until the
operation
was complete, right?

Just curious about the inner workings of R.

-- 
---------------------------------------
David L. Van Brunt, Ph.D.
mailto:dlvanbrunt@gmail.com

"If Tyranny and Oppression come to this land, it will be in the guise of
fighting a foreign enemy."
--James Madison

	[[alternative HTML version deleted]]

Yes, at the end... but I'm getting memory allocation errors and outright
crashes DURING the operation when assigning into the same variable... still
waiting for the alternative to survive or not...


On 3/23/07, Bert Gunter <gunter.berton@gene.com>
wrote:
>
> Actually... there can be more than one "working copy".
>
> Clearly, at the end, when you assign back to the same object, you use less
> memory.
>
> Cheers,
> Bert Gunter
> Genentech Nonclinical Statistics
> South San Francisco, CA 94404
> 650-467-7374
>
>
> -----Original Message-----
> From: r-help-bounces@stat.math.ethz.ch
> [mailto:r-help-bounces@stat.math.ethz.ch] On Behalf Of David L. Van Brunt,
> Ph.D.
> Sent: Friday, March 23, 2007 11:15 AM
> To: R-Help List
> Subject: [R] memory, speed,and assigning results into new v. existing
> variable
>
> I have a very large data frame, and I'm doing a conversion of all
columns
> into factors. Takes a while (thanks to folks here though, for making
> faster!), but am wondering about optimization from a memory perspective...
>
> Internally, am I better off assigning into a new data frame, or doing one
> of
> these:
>
> dataframe<-someoperation(dataframe)
>
> It would seem that re-assigning into the same data frame *might* be more
> efficient in that I don't have to double the memory with 2 objects, but
> then
> again.. there'd have to be a "working copy" in memory until
the operation
> was complete, right?
>
> Just curious about the inner workings of R.
>
> --
> ---------------------------------------
> David L. Van Brunt, Ph.D.
> mailto:dlvanbrunt@gmail.com
>
> "If Tyranny and Oppression come to this land, it will be in the guise
of
> fighting a foreign enemy."
> --James Madison
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@stat.math.ethz.ch mailing list
> 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.
>
>

-- 
---------------------------------------
David L. Van Brunt, Ph.D.
mailto:dlvanbrunt@gmail.com

"If Tyranny and Oppression come to this land, it will be in the guise of
fighting a foreign enemy."
--James Madison

	[[alternative HTML version deleted]]