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