Read the troubleshooting section on the home page:
http://ryacas.googlecode.com . Some common problems are that you did
not install yacas itself (issue yacasInstall() command without args
and it will do that for you) and that you are using the wrong version
of the XML package.
> library(Ryacas)
Loading required package: XML> a <- Sym("a")
> a
[1] "Starting Yacas!"
expression(a)
On Thu, Dec 17, 2009 at 2:06 PM, Gavin Steininger <gsteinin at uvic.ca>
wrote:> I have been trying to get the Ryacas package to work without any
> success. I do not seem to be able to the "Sym" function work, for
> example:
>
>> library(XML)
>> library(Ryacas)
>> a=Sym("a")
>> a
> Error in summary.connection(x) : invalid connection
>
> I am windows XP ?with R 2.10
>
> Thanks for you help
>
> gavin amw steininger
>
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