Discrepancy in help for object.size() and question on how to round object sizes

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Discrepancy in help for object.size() and question on how to round object sizes

Jennifer Lyon
I think there is a discrepancy In the help for object.size().

In the usage section there is the comment:
## S3 method for class 'object_size':

while in the value section there is the text:
 An object of class ‘"object.size"’ ...

And R itself says:

 > class(object.size(letters))
[1] "object_size"

Also, I was trying to print out object sizes in Kb, but rounded to
whole number of units, but I could not
figure out how to do that without having to replicate the math in the
print method for object.size.

> tmp<-numeric(100000)
> object.size(tmp)
800024 bytes

> print(object.size(tmp), units="Kb")
781.3 Kb

What I want is 781 Kb, but it wasn't obvious how to get there. The
following seemed wrong, and
didn't work:

> print(signif(object.size(tmp),1), units="Kb")
781.2 Kb
> print(round(object.size(tmp)), units="Kb")
781.3 Kb

I know I can just get the result in bytes and divide by 1024, and then
round, but it seemed like there
should be a more straightforward way, so any suggestions are welcome.

Thanks!

Jen

> sessionInfo()
R version 2.11.1 (2010-05-31)
i686-pc-linux-gnu

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
 [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
 [5] LC_MONETARY=C              LC_MESSAGES=en_US.UTF-8
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  utils     datasets  grDevices methods   base

other attached packages:
[1] RColorBrewer_1.0-2

loaded via a namespace (and not attached):
[1] tools_2.11.1

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Re: Discrepancy in help for object.size() and question on how to round object sizes

Duncan Murdoch-2
On 25/07/2010 7:58 AM, Jennifer Lyon wrote:

> I think there is a discrepancy In the help for object.size().
>
> In the usage section there is the comment:
> ## S3 method for class 'object_size':
>
> while in the value section there is the text:
>  An object of class ‘"object.size"’ ...
>
> And R itself says:
>
>  > class(object.size(letters))
> [1] "object_size"

Thanks, I'll fix the typo.

>
> Also, I was trying to print out object sizes in Kb, but rounded to
> whole number of units, but I could not
> figure out how to do that without having to replicate the math in the
> print method for object.size.

I don't think there's any simple way to do it.  You can see the print
method using

utils:::print.object_size

and it has one decimal point hard coded into the calls to round().  So
you could copy that print method and change the rounding, or if you
don't mind sloppy truncating rather than proper rounding, you could do a
hack like this:

wholesize <- function(x, units="b") {
    size <- capture.output(print(object.size(x), units=units))
    cat( sub("\\.[[:digit:]]", "", size), "\n" )
}

We could add a "decimals" argument to the version in R, but I'd rather
not:  it just introduces another point for people to confuse formatting
with rounding, e.g. if the size is exactly 1000 Kb, should it be printed
as 1000.0 Kb if you ask for 1 decimal?  (Currently it will print as 1000
Kb.)

Duncan Murdoch

>
>> tmp<-numeric(100000)
>> object.size(tmp)
> 800024 bytes
>
>> print(object.size(tmp), units="Kb")
> 781.3 Kb
>
> What I want is 781 Kb, but it wasn't obvious how to get there. The
> following seemed wrong, and
> didn't work:
>
>> print(signif(object.size(tmp),1), units="Kb")
> 781.2 Kb
>> print(round(object.size(tmp)), units="Kb")
> 781.3 Kb
>
> I know I can just get the result in bytes and divide by 1024, and then
> round, but it seemed like there
> should be a more straightforward way, so any suggestions are welcome.
>
> Thanks!
>
> Jen
>
>> sessionInfo()
> R version 2.11.1 (2010-05-31)
> i686-pc-linux-gnu
>
> locale:
>  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
>  [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
>  [5] LC_MONETARY=C              LC_MESSAGES=en_US.UTF-8
>  [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
>  [9] LC_ADDRESS=C               LC_TELEPHONE=C
> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>
> attached base packages:
> [1] stats     graphics  utils     datasets  grDevices methods   base
>
> other attached packages:
> [1] RColorBrewer_1.0-2
>
> loaded via a namespace (and not attached):
> [1] tools_2.11.1
>
> ______________________________________________
> [hidden email] 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.

______________________________________________
[hidden email] 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.