Re: How to choose real positive solutions?

*To*: mathgroup at smc.vnet.net*Subject*: [mg74306] Re: How to choose real positive solutions?*From*: Peter Breitfeld <phbrf at t-online.de>*Date*: Sun, 18 Mar 2007 00:44:12 -0500 (EST)*References*: <etg46h$ijg$1@smc.vnet.net>

mandix schrieb: > Hi, > suppose I want to solve a system of 3 equations and 3 unknowns > (polynomial of degree whatever, say n). Is there a way to tell NSolve > to return only real and positive solutions (and ignore the rest)? > > thanks you so much, > > Manfred > Manfred, first define a pattern which matches complex Numbers e.g: MuComplex= _?(!FreeQ[Chop[N[#],10^-13],_Complex]&) then do: DeleteCases[NSolve["whatever"],MuComplex] Gruss Peter -- ==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-== Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de