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Re: A bug-looking behavior during integration

  • To: mathgroup at smc.vnet.net
  • Subject: [mg130004] Re: A bug-looking behavior during integration
  • From: Scott Hemphill <hemphill at hemphills.net>
  • Date: Sun, 3 Mar 2013 22:59:36 -0500 (EST)
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  • Reply-to: hemphill at alumni.caltech.edu

daniel.lichtblau0 at gmail.com writes:

[snip]

> Yes, it looks like this runs into some fragility in the UnitStep handling code. To work around that area I'd suggest using a Piecewise equivalent.
>
> In[2]:= Integrate[                                                              
>          Piecewise[{{1, Sqrt[Sqrt[x^2 + y^2] + x] - .7*Sqrt[x^2 + y^2] >= 0}},  
>            0], {x, -Infinity, Infinity}, {y, -Infinity, Infinity}]              
>
> Out[2]= 19.6268

Or, replacing the ".7" with 7/10, you get:

        15000 Pi
Out[1]= --------
          2401

Scott
-- 
Scott Hemphill	hemphill at alumni.caltech.edu
"This isn't flying.  This is falling, with style."  -- Buzz Lightyear



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