[Rd] Imports, importFrom slow (for Matrix)

Gábor Csárdi csardi.gabor at gmail.com
Tue Oct 29 15:25:36 CET 2013

Unfortunately that seems to be (almost) just as slow.

~$ time Rscript -e 'Matrix::summary; ls()' > /dev/null
real 0m2.785s
user 0m2.668s
sys 0m0.112s


On Tue, Oct 29, 2013 at 10:11 AM, Prof Brian Ripley
<ripley at stats.ox.ac.uk> wrote:
> On 29/10/2013 14:03, Gábor Csárdi wrote:
>> Dear All,
>> before its latest version my package had 'Imports: Matrix' in its
>> DESCRIPTION file, but it did not import anything in NAMESPACE. Rather,
>> some functions explicitly loaded Matrix, as they needed. The reason
>> for this was that importing Matrix is really slow, and only very few
>> igraph functions need it. (I guess Matrix is slow because of the many
>> registered names, but that is another question.)
>> # Empty session:
>> ~$ time Rscript -e 'ls()' > /dev/null
>> real 0m0.251s
>> user 0m0.196s
>> sys 0m0.049s
>> # Without importing from Matrix:
>> ~$ time Rscript -e 'library(igraph); ls()' > /dev/null
>> Loading required package: methods
>> real 0m0.419s
>> user 0m0.363s
>> sys 0m0.049s
>> # Adding importFrom(Matrix, sparseMatrix) to NAMESPACE:
>> ~$ time Rscript -e 'library(igraph); ls()' > /dev/null
>> Loading required package: methods
>> real 0m2.963s
>> user 0m2.844s
>> sys 0m0.115s
>> This solution was fine with me, especially because other packages
>> depending on igraph and using Matrix through igraph worked fine on the
>> CRAN build servers, as igraph brought Matrix with it. (The build
>> servers don't have recommended packages like Matrix available by
>> default.)
>> Recently, R CMD check does not allow me to list Matrix at Imports
>> without importing something from it. This is understandable, because
>> it is an inconsistency after all, but caused some headache for me.
>> A 3s loading time for a package is IMHO much longer than ideal,
>> especially that loading R itself is ten times faster. So I definitely
>> don't want to import from Matrix right now.
>> The solution I settled with was to include Matrix in 'Suggests', and
>> the load it selectively, as before. Now some packages depending on
>> igraph are failing on the CRAN build servers, which don't have Matrix
>> installed for these packages. (Luckily they are probably not failing
>> for users, because most users do have the recommended packages.)
>> In summary, it would be great to speed up imports.
>> Another solution would be some mechanism that allows me to import from
>> a package as needed, not at the package loading time. Something like a
>> delayed importFrom().
> That is what Matrix:: does.  There is nothing like enough here for us to
> tell why it would not suffice for you.  (If you want to import something
> occasionally and then use it very many times, make a local copy.)
>> Just wanted to bring up this issue.
>> Best,
>> Gabor
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
> --
> Brian D. Ripley,                  ripley at 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 272866 (PA)
> Oxford OX1 3TG, UK                Fax:  +44 1865 272595
> ______________________________________________
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