Re: Solve[] and Eliminate[] choke on simple systems of equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg74795] Re: [mg74719] Solve[] and Eliminate[] choke on simple systems of equations*From*: bsyehuda at gmail.com*Date*: Thu, 5 Apr 2007 04:14:54 -0400 (EDT)

Well you may have discovered it already, but there is a comma missing (12'th equation). After correcting this, Mathematica solves this with a fraction of a second regards yehuda On 4/2/07, darrell.long at gmail.com <darrell.long at gmail.com> wrote: > > Hi, > > I am trying to convert some of my old stuff from another system to > Mathematica. > Below is an example of a Markov model that takes the other system a couple > of > seconds to solve, but Mathematica chews on forever (I gave up after > about 30 minutes). > > Since I'm a Mathematica newbie, perhaps there is some limitation I am > not aware of? > > eqns = {3*L*P333 == U*(P323 + P322 + P223 + P221 + P120), > (K + 2*L + U)*P323 == 3*L*P333, > (K + 2*U + L)*P313 == 2*L*P323, > (2*L + U)*P322 == 2*U*P312, > (2*U + L)*P312 == 2*L*P322 + 3*U*P302, > 3*U*P302 == L*P312 + L*P313, > (2*L + U)*P223 == U*(2*P213 + P212) + 2*U*P313 + U*(2*P113 + P111) + > K*P323, > (K + 2*U + L)*P213 == 2*L*P223, > (2*U + L)*P212 == L*P221 + 2*U*P202, > 3*U*P202 == L*(P213 + P212 + P211), > (2*L + U)*P221 == U*(P212 + 2*P211), > (2*U + L)*P211 == L*P221 + U*P202 > (L + 2*U)*P113 == K*P313 + K*P213 + U*P102, > 3*U*P102 == L*P113 + L*P111, > (2*U + L)*P111 == 2*U*P102 + 2*L*P120, > (2*L + U)*P120 == U*P111, > P333 + P323 + P313 + P322 + > P312 + P302 + P223 + P213 + P212 + P202 + P221 + P211 + P113 + > P102 + > P111 + P120 == 1} > vars = {P333, P323, P313, P322, P312, P302, P223, P213, P212, P202, > P221, > P211, P113, P102, P111, P120} > > A = Solve[eqns, vars] > > >