[R] [R-pkgs] New package Ryacas

[Gabor Grothendieck]

Its pretty limited right now but you can do this:

> library(Ryacas)
> d <- List(List(1, 0, 0), List(0, 1, 0), List(0, 0, 1))
> a <- Sym("a")
> a * d
expression(list(list(a, 0, 0), list(0, a, 0), list(0, 0, a)))
> PrettyForm("%")
/                    \
| ( a ) ( 0 ) ( 0 )  |
|                    |
| ( 0 ) ( a ) ( 0 )  |
|                    |
| ( 0 ) ( 0 ) ( a )  |
\                    /

The ASCII representation of the matrix will look correct in R although its
possible that the email process munges it up so it may not look right
when you receive this.

Also there are also matrix examples on the home page, in the Ryacas vignette
and in the Ryacas-Sym vignette.

Note that by mistake the vignette labelled Ryacas-Sym in the package
itself is actually a copy of the Ryacas vignette so to see the actual
Ryacas-Sym vignette currently one must look at the one in the source repository:
http://ryacas.googlecode.com/svn/trunk/inst/doc/Ryacas-Sym.pdf



On 10/16/06, Cleber N. Borges <cborges at iqm.unicamp.br> wrote:
> Hello,
>
> First,
> I would like to congratulations for very cool package! It's very
> nice
> idea!...
> Secondly,
> Is there a way to send R'objects (variables) to yacas and make
> symbolic
> operations??
> for example:
>
> d <- diag(3)
> a <- "A"
>
> yacas(   d * a )
>
> Thanks,
> Cleber Borges
>
>
> Gabor Grothendieck wrote:
>
> >Ryacas is an R interface to the free yacas computer algebra
> >system.  Ryacas allows one to send R expressions,
> >unprocessed yacas strings and certain other R objects to a
> >separate yacas process from R and get back the result.  It
> >also has facilities for manipulating yacas strings and R
> >expressions destined for yacas processing.
> >
> >It can be used for exact arithmetic, symbolic math, ASCII
> >pretty printing and translating R to TeX.
> >
> >
> >Online info.  For overview, pointers to additional
> >information, installation instructions and a sample session
> >see:
> >
> >    http://code.google.com/p/ryacas/
> >
> >The vignettes can be viewed online here:
> >
> >    http://ryacas.googlecode.com/svn/trunk/inst/doc/Ryacas.pdf
> >    http://ryacas.googlecode.com/svn/trunk/inst/doc/Ryacas-Sym.pdf
> >
> >
> >More. Once Ryacas is installed, pointers to additional
> >information can be found with these R commands:
> >
> >    library(Ryacas)
> >    package?Ryacas
> >
> >
> >---
> >
> >
>
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