Simplified Integration Problem
- To: mathgroup at smc.vnet.net
- Subject: [mg35564] Simplified Integration Problem
- From: Arnold Gregory Civ AFRL/SNAT <Gregory.Arnold at wpafb.af.mil>
- Date: Fri, 19 Jul 2002 06:08:21 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Here's a slightly simplified version of the integration problem I presented the other day: int=Integrate[UnitStep[1 - t^2 - c^2*(-4*t + 8*t^3)^2], {t, -1, 1}]; int /. c->0 Result:2 int /. c->0. Result:0. int /. c->3 Result:2 int /. c->3. Result:0.28817 In fact, "int /. c-> any rational" always yields 2!!! NIntegrate gets the right answers: NIntegrate[UnitStep[1 - t^2 - 0^2*(-4*t + 8*t^3)^2], {t, -1, 1}, MinRecursion->5,MaxRecursion->30] Result: 2 NIntegrate[UnitStep[1 - t^2 - 2^2*(-4*t + 8*t^3)^2], {t, -1, 1}, MinRecursion->5,MaxRecursion->30] Result: 0.28817 Plot[int,{c,-5,5}] also gets the right results. Any help or insight into why Integrate isn't working would be greatly appreciated! Greg