Re: Problem NSolve
- To: mathgroup at smc.vnet.net
- Subject: [mg90673] Re: Problem NSolve
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Fri, 18 Jul 2008 04:04:08 -0400 (EDT)
On 7/17/08 at 5:36 AM, jorgecerrillo at gmail.com (Jorge) wrote: >Hello! To begin to ask for excuses you for my English poor level... >I am a Spanish student of Chemical Engineering. Now I am employed at >the simulation of a series of chemical reactions with Mathematica. >As soon as I have programmed the problem to resolving, 23 equations >with 23 variables, I use the function Nsolve, but the program >returns to me the following message of mistake >General::ivar: 0 is not a valid variable. >> >I have programmed my problem of the following form: >ecu{lhs1==0,lhs2=0,...,lhs23} sol=Nsolve[ecu{var1,var2,...,var23}] >Might someone help? There really is no way for someone to determine what the specific problem is without the code leading to this error. Most likely, there is a typo in what you entered. Possibly using "=" where you meant to use "==". In fact, the second argument to the function ecu in the snippet you posted sets lhs2 to 0. Perhaps this should have been lhs2==0 instead.