Re: numerical solution of an ODE doesn't make sense

*To*: mathgroup at smc.vnet.net*Subject*: [mg49543] Re: [mg49520] numerical solution of an ODE doesn't make sense*From*: Selwyn Hollis <sh2.7183 at misspelled.erthlink.net>*Date*: Fri, 23 Jul 2004 05:59:31 -0400 (EDT)*References*: <200407220646.CAA21094@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

On Jul 22, 2004, at 2:46 AM, Ita wrote: > Hello, and thanks in advance to any response. > I solved a 2nd degree ode with NDSolve for the unknown x(t) for 2 time > domains: 0<t<100 and 0<t<700, with the same boundary conditions. > than I ploted the two solutions for 0<t<20, and they came out > different ! it > is like the solution in t<20 is influenced by the solution in t>100 - > it > doesn't make sense. > thanks, > Itamar. > Most likely it's because of different step sizes. Use the MaxStepSize or MaxStepFraction option; e.g., MaxStepSize->1 or MaxStepFraction->1/100. ----- Selwyn Hollis http://www.appliedsymbols.com (edit reply-to to reply)

**References**:**numerical solution of an ODE doesn't make sense***From:*"Ita" <kitamar@actcom.net.il>