[R] New package Ryacas

[Gabor Grothendieck]

On 10/16/06, Cleber N.Borges <klebyn at yahoo.com.br> wrote:
> Hello Gabor
>
> I try these example, but I obtain some errors.
>
>
> *First example*
>
> > yacas("a * Identity(3)")
> expression(list(list(a, 0, 0), list(0, a, 0), list(0,
> 0, a)))
>
>  it's ok , but the next command:
>
> > PrettyForm("%")
> Error in PrettyForm("%") : no applicable method for
> "PrettyForm"

Bug.  Seems 0.2-2 is missing a PrettyForm.default method.  Try
adding the PrettyForm.default <- line shown before the rest:

PrettyForm.default <- PrettyForm.Sym
d <- List(List(Sym(1), 0, 0), List(Sym(0), 1, 0), List(Sym(0), 0, 1))
a <- Sym("a")
a * d
PrettyForm("%")


> >
>
> If I make a little modification ( set a variable in
> YACAS), I obtain right behavior.
>
> > yacas("TEST := a * Identity(3)")
> expression(list(list(a, 0, 0), list(0, a, 0), list(0,
> 0, a)))
> >
> > yacas("PrettyForm(TEST)")
> /                    \
> | ( a ) ( 0 ) ( 0 )  |
> |                    |
> | ( 0 ) ( a ) ( 0 )  |
> |                    |
> | ( 0 ) ( 0 ) ( a )  |
> \                    /
> >
>
> I make a test for all example in "Ryacas.pdf" and all
> works for me! :-)
>
>
> *Second example*
>
> > d <- List(List(1, 0, 0), List(0, 1, 0), List(0, 0,
> 1))
> Error in List(1, 0, 0) : no applicable method for
> "List"

Similar problem.  Try issuing this statement:

List.default <- List.Sym

before running the rest.

> >
>
> > d <- yacas( "List(List(1, 0, 0), List(0, 1, 0),
> List(0, 0, 1))" )
> > d
> expression(list(list(1, 0, 0), list(0, 1, 0), list(0,
> 0, 1)))
> >
>
> GUESS:
> When I use the commands whitout yackas() statement,
> the error raise up.
>
> > a <- Sym("a")
> > a * d
> a * list( list( 1 , 0 , 0 ) , list( 0 , 1 , 0 ) ,
> list( 0 ,
> 0 , 1 ) )
> > PrettyForm("%")
> Error in PrettyForm("%") : no applicable method for
> "PrettyForm"
> >
>
> > yacas("PrettyForm(%)")
> a * list( list( 1 , 0 , 0 ) , list( 0 , 1 , 0 ) ,
> list( 0 ,
> 0 , 1 ) )
>
>
>
> Thanks for your attention!
>
>
> Cleber Borges
>
>
>
>
> >Here is a slightly shorter way to do it although it
> involves passing
> >a yacas string directly:
> >
> >>yacas("a * Identity(3)")
> >
> >expression(list(list(a, 0, 0), list(0, a, 0), list(0,
> 0, a)))
> >
> >>PrettyForm("%")
> >
> >/                    \
> >| ( a ) ( 0 ) ( 0 )  |
> >|                    |
> >| ( 0 ) ( a ) ( 0 )  |
> >|                    |
> >| ( 0 ) ( 0 ) ( a )  |
> >\                    /
> >
> >
> >On 10/16/06, Gabor Grothendieck
> <ggrothendieck at gmail.com> wrote:
> >
> >>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
> >>>
> >>>
>
>
>
>
>
>
>
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