[R] general inverse solver?
ba208 at exeter.ac.uk
Wed Feb 11 10:25:56 CET 2009
In a different perspective the sage project might also be an option,
it seems to interface to Maxima and R among other things. I haven't
tested it myself though.
PS: sagemath.org is a well-thought website, perhaps a good
inspiration for the new design discussed recently?
On 11 Feb 2009, at 07:56, Hans W. Borchers wrote:
> Gabor Grothendieck <ggrothendieck <at> gmail.com> writes:
>> I am not sure what the point of all this is.
> The point of all this is:
> 1. Some users of R here on the list apparently would like to have
> more powerful
> CAS functionalities than Yacas can provide.
> 2. Many of the solution hints to Ryacas on this list were simply not
> solving the
> resp. problem, so the 80/20 statement of yours may be downright wrong.
> 3. Maxima does incorporate a socket server and can be integrated
> into other
> systems, see EULER (do you never listen?).
> What are you mourning about? Of course, it was great that you made
> Yacas for R. But others have the right to discuss their wishes here
> w/o being
> 'slammed' every time with questionable hints to Ryacas.
> I agree arguments have been exchanged and we should stop here. After
> discussion, I wish someone would think about an Rmaxima package
> (along the lines
> of EULER, e.g.), I cant do it, unfortunately.
> Hans Werner Borchers
>> This is an R list, not a CAS list. The recommendation to use yacas
>> is based on
>> the fact that there is an interface between R and yacas. There is
>> interface between
>> R and Maxima so Maxima is not in the running. Anyone who has used
>> Maxima knows that
>> is an impressive piece of software but that's not the point.
>> Regarding, why there is no interface to Maxima, its because its
>> to interface to
>> Maxima than yacas. There are two problems here:
>> 1. Maxima does not incorporate a socket server as far as I know.
>> You would have to write it and that may or may not need an in depth
>> understanding of Maxima to do so but in any case represents work.
>> With yacas you don't have to write a server since yacas itself
>> contains a server. Just run:
>> yacas --server .,.
>> and the server side is done. (In the case of yacas it would also be
>> possible to use its C interface for an in-process interface or
>> the java interface of the new java version of yacas. With Maxima
>> it would be more problematic since its written in Lisp.)
>> 2. Once you have created some sort of communications channel
>> then what? If you want more than a crude interface that passes
>> an unprocessed character string to the CAS and then passes one
>> back then you will want to translate between R and the CAS. With
>> yacas, OpenMath facilitates this greatly.
>> The end result is that its more work to meaningfullly interface with
>> Maxima than with yacas yet yacas satisfies the majority of
>> needs of a CAS. There is the minority who need more powerful
>> algorithms but I think it was a reasonable step to handle the 80%
>> that can be accommodated most easily first by using yacas. The
>> remaining 20%, which is what the other respondents to this thread
>> are discussing will in part be addressed in the future possibly, in
>> part, by the second project I am working on now. Perhaps some
>> would quibble with the 80/20 and if you are in the 20 it probably
>> seems like 100 but we will never settle that question definitively.
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