Nintegration - numerical integration converges too slow
- To: mathgroup at smc.vnet.net
- Subject: [mg38127] Nintegration - numerical integration converges too slow
- From: "Fitchard, Ann (PSAF)" <PSAF at chevrontexaco.com>
- Date: Tue, 3 Dec 2002 04:33:57 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
I am a new Mathematica user with a numerical integration problem. My 2D Nintegration gives the warning "slwcon" (numerical integration converges too slow). I am integrating over a thin strip through a 2D Interpolating Function. The Interpolating function is zero for most values. All stips pass through some non-zero region. When the strip is mostly in the non-zero region there is no problem. Howvever, when the strip passes through only a small part of the non-zero region, the warning occurs and the integration is slow. The integration parameters I have so far found to work best are: WorkingPrecision -> 9, AccuracyGoal ->Infinity, Precision Goal -> 2, Method -> Gausskronron. If I increase the PrecisionGoal both the number of warnings and the time increase. Can you suggest a better set of parameters. Thank you in advance. Ann Fitchard