How to change time stepsize for Integration

*To*: mathgroup at smc.vnet.net*Subject*: [mg33956] How to change time stepsize for Integration*From*: Winston Garira <uceswga at ucl.ac.uk>*Date*: Wed, 24 Apr 2002 01:22:24 -0400 (EDT)*Reply-to*: Winston Garira <uceswga at ucl.ac.uk>*Sender*: owner-wri-mathgroup at wolfram.com

Hi! Can anyone help me on this one: Pends[init_, time_, {c_, w_, p_}] := Module[{}, pend = NDSolve[{x''[t] + c x'[t] + (1 + p Cos[w t])Sin[x[t]] == 0, x[0] == init[[1]], x'[0] == init[[2]]}, {x}, {t, 0, time}, MaxSteps -> 200000]; xd[t_] := x[t] /. pend[[1]]; xdd[t_] := x'[t] /. pend[[1]];]; c = 0.1; w = 0.30; p = 1.1; Pends[{1.37, 0}, 5000, {c, w, p}]; plt = Plot[{t, xd[t], xdd[t]}, {t, 0, 500}]; I want to reduce the time stepsize in my numerical integration with mathematica. Each time I try to get coordinates generated from the command Plot[ ......, {t, tmin, tmax}]; or Table[......, {t, tmin, tmax}]; I always notice that in all these case time stepsize = 1. Is there anyway I can reduce the the timestep to say, time stepsize =0.001 in the above numerical integration using NDsolve. Thanks in advance Winston