Why the difference?
- To: mathgroup@smc.vnet.net
- Subject: [mg10760] Why the difference?
- From: Ram Kochhar <rameric@eskimo.com>
- Date: Mon, 2 Feb 1998 00:44:56 -0500
- Organization: Eskimo North (206) For-Ever
Consider the following evaluations
ans1 = Integrate[Log[x^2+y^2],{x,-1,1},{y-1,1}]
expr = Log[(x-a)^2 + (y-b)^2]
ans2 = Integrate[expr,{x,-1,1},{y,-1,1}] /. {a->0,b->0}
ans3 = Integrate[expr,{x,-1,,a,1},{y,-1,b,1}] /. {a->0,b->0}
Mathematica gives different results. Difference is probably due to
branch cuts.
Is there a way to calculate these so that mathematica gives same
result? I am
interested in near field interactions of Newtonian potentials. I could
subdivide
the domain of integration in this particular case. But is there another
way?
Ram kochhar
rameric@eskimo.com