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

*To*: mathgroup at smc.vnet.net*Subject*: [mg74740] Re: [mg74719] Solve[] and Eliminate[] choke on simple systems*From*: anguzman at ing.uchile.cl*Date*: Tue, 3 Apr 2007 00:27:25 -0400 (EDT)

Thanks. It was indeed a missing comma. The extra equation shouldn't hurt (it was a direct reading of the Markov model). On Apr 2, 2007, at 9:08 AM, anguzman at ing.uchile.cl wrote: > Hello: > I think there is comma missing at the end of equation 12. However, > it would imply 17 equations for 16 variables. I eliminated the > first and Mathematica solve the system in a few seconds. > > > Atte. Andres Guzman > > > > > > > darrell.long at gmail.com ha escrito: > >> 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] >> >> >> > > > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program. > ----- Terminar mensaje reenviado ----- ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.