timing problems in mathematica

*To*: mathgroup at yoda.physics.unc.edu*Subject*: timing problems in mathematica*From*: BENNINGA at wilma.wharton.upenn.edu*Date*: Tue, 6 Oct 92 13:17 EDT

Can someone help me? The following Mathematica program produces a triangular matrix of real numbers. My problem is that the TIMING differs each time I run the program. Here are some sample times (in seconds) for tmax=5: 19.28, 19.99, 20.93, 21.86,.66.02. The last time was when I returned to tmax=5 after running the program for tmax=30 (that one took 2090.34 seconds!). I'm running Mma on a 80486 under MS-Windows. I should add that I'm new to the program. While I'm at it: Does anyone out there have a problem with a jumpy cursor? Occassionally disappearing text? Thanks, Simon Benninga Finance Department, Wharton School Univ. of Pennsylvania BENNINGA at WHARTON.UPENN.EDU HERE'S THE PROGRAM Clear[beta1,beta2,gamma1,gamma2,s0,LHS,s,j,t] gamma1=2;gamma2=14; s0=0.45; beta1=0.9;beta2=0.95; tmax=5; initial=(1-s0)^gamma2/s0^gamma1; LHS[t_,s_]:=initial*(beta1/beta2)^t*(s^gamma1/(1-s)^gamma2); c[t_,j_]:=Which[j<=t,FindRoot[LHS[t,s]==u^j*d^(t- j),{s,0.5}],j>t,0]; (* The following command produces a matrix of numbers only: *) cons=Table[c[t,j][[1,2]],{t,0,tmax},{j,0,t}] ;