Hi I'm developing an R package that needs to execute some code written in pari/gp. I've used this before from an R package (elliptic) but the interface is very basic: the R function creates a string such as the following: string <- echo ' ellwp ([ 2+0*I , 0+2*I ], 1+0*I )' | gp -q And then system(string) returns the output from gp which then needs to be text processed (translating "I" to "i", etc). I don't think this approach would work under Windows. Does anyone have any experience of calling pari/gp from R? Or any ideas for a more portable method than the one above? [ PARI/GP is a widely used computer algebra system designed for fast computations in number theory. It is freely available at http://pari.math.u-bordeaux.fr/ ] -- Robin Hankin Uncertainty Analyst National Oceanography Centre, Southampton European Way, Southampton SO14 3ZH, UK tel 023-8059-7743
On Windows XP either of these work under R. Here echo and findstr
are builtin Windows commands but you could substitute others:
system("cmd /c echo abc | findstr a", intern = TRUE)
shell("echo abc | findstr a", intern = TRUE)
If its necessary to special case it then note that the
R variable .Platform$OS.type equals "windows" on Windows.
On 7/25/06, Robin Hankin <r.hankin at noc.soton.ac.uk>
wrote:> Hi
>
> I'm developing an R package that
> needs to execute some code written in pari/gp.
>
> I've used this before from an R package (elliptic) but the interface
> is very
> basic: the R function creates a string such as the following:
>
> string <- echo ' ellwp ([ 2+0*I , 0+2*I ], 1+0*I )' | gp -q
>
> And then
>
> system(string)
>
> returns the output from gp which then needs to be text processed
> (translating "I"
> to "i", etc).
>
> I don't think this approach would work under Windows.
>
> Does anyone have any experience of calling pari/gp from R?
>
> Or any ideas for a more portable method than the one above?
>
>
>
>
> [
> PARI/GP is a widely used computer algebra system designed for fast
> computations
> in number theory. It is freely available at
>
> http://pari.math.u-bordeaux.fr/
> ]
>
>
> --
> Robin Hankin
> Uncertainty Analyst
> National Oceanography Centre, Southampton
> European Way, Southampton SO14 3ZH, UK
> tel 023-8059-7743
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
On 7/25/06, Robin Hankin <r.hankin at noc.soton.ac.uk> wrote:> Hi > > I'm developing an R package that > needs to execute some code written in pari/gp. > > I've used this before from an R package (elliptic) but the interface > is very > basic: the R function creates a string such as the following: > > string <- echo ' ellwp ([ 2+0*I , 0+2*I ], 1+0*I )' | gp -q > > And then > > system(string) > > returns the output from gp which then needs to be text processed > (translating "I" > to "i", etc). > > I don't think this approach would work under Windows.I know nothing about pari/gp, but I believe it does work on Windows too. There is system() command available on the Windows version too, but with slightly different arguments (than on Linux say). Piping is available on Windows too, e.g. "dir | sort", although you should be able to get around that by writing to file instead and using ">" and "<". You should be careful if your 'string' gets really long. Then it is much better to have a BAT file (and an sh file on Linux) to run your external calls, alternatively you call system() multiple times. However, I would be suprised if 'ellwp' wouldn't accept files as input too. /Henrik> Does anyone have any experience of calling pari/gp from R? > > Or any ideas for a more portable method than the one above? > > > > > [ > PARI/GP is a widely used computer algebra system designed for fast > computations > in number theory. It is freely available at > > http://pari.math.u-bordeaux.fr/ > ] > > > -- > Robin Hankin > Uncertainty Analyst > National Oceanography Centre, Southampton > European Way, Southampton SO14 3ZH, UK > tel 023-8059-7743 > > ______________________________________________ > R-devel at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > >