I've pretty much abandoned Numbers because I find it rather underpowered. I'm now using NeoOffice Calc which is free, and I have written a macro to perform a Nelder-Mead optimization, which should be adaptable to the circular reference calculation problem discussed here, although you would need to restructure your calculation. I posted the Nelder-Mead solver code on the OpenOffice Forum board here:
http://www.oooforum.org/forum/viewtopic.phtml?t=92089It's just a matter of copying the code and pasting it into the macro editor. The Nelder-Mead solver can handle essentially an unlimited number of variables, and is more versatile and easier to implement than Newton Raphson because it's not necessary to calculate derivatives. I've used it extensively to solve equations which cannot be expressed in closed form. If you want to try this and have any questions about it, I'd be happy to help.
BTW, for anyone that tried early versions of NeoOffice or OpenOffice and were disgusted by the user unfriendliness, be advised that it's now vastly improved.
