R help - Oct 2008 - back-solver: any R thing like TK!Solver?

Just thought I'd ask.  For those who've never seen TK!Solver, I strongly
recommend taking a look.  So far as I can tell, it's the only product of 
its type available, retail or open source, for any platform.
What makes TK!Solver so cool is that it adaptively back-solves pretty 
much any unknown from any set of equations you give it.  (or vector full 
of unknowns, producing a vector of results, and so on)

I've been bummed for years 'cause the original package ran on Macs 
(inthe OS-4 days) but is now only available for WinBlows -- and is 
getting expensive.  So:  what sort of back-solver tools or packages are 
there in R, if any?

thanks
Carl

Excel has a solver and Ryacas has limited ability to
do symbolic solving:
> library(Ryacas)
> x <- Sym("x")
> y <- Sym("y")
> Solve(List(x + y == 1, x - y == 1), List(x, y))
[1] "Starting Yacas!"
expression(list(list(x == 1 - y, y == 0)))


On Sat, Oct 4, 2008 at 10:07 AM, Carl Witthoft <carl at witthoft.com>
wrote:
> Just thought I'd ask.  For those who've never seen TK!Solver, I
strongly
> recommend taking a look.  So far as I can tell, it's the only product
of its
> type available, retail or open source, for any platform.
> What makes TK!Solver so cool is that it adaptively back-solves pretty much
> any unknown from any set of equations you give it.  (or vector full of
> unknowns, producing a vector of results, and so on)
>
> I've been bummed for years 'cause the original package ran on Macs
(inthe
> OS-4 days) but is now only available for WinBlows -- and is getting
> expensive.  So:  what sort of back-solver tools or packages are there in R,
> if any?
>
> thanks
> Carl
>
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