Re: UnitStep in Mathematica 4.1
- To: mathgroup at smc.vnet.net
- Subject: [mg38220] Re: [mg38180] UnitStep in Mathematica 4.1
- From: Vladimir Bondarenko <vvb at mail.strace.net>
- Date: Thu, 5 Dec 2002 03:35:00 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
pillsy at mac.com (Matt Pillsbury) wrote on Wednesday, December 04, 2002, 4:26:04 AM :
MP> I have been relying on the UnitStep function in a project, and in
MP> general it seems to work pretty nicely. However, there is one simple
MP> problem that I'm having with it. Mathematica doesn't know that
MP> Integrate[UnitStep[-x] UnitStep[x], {x,-1,1}]
MP> should be zero. Is this because the integrand is 0 everywhere but at
MP> the origin, where it is 1, and Mathematica doesn't know what to do
MP> with the contribution from a set of measure zero? Or am I doing
MP> something else wrong?
MP> And is there a simple fix for my problem?
The Integration package written by Roger Germundsson does what you
want.
In[1] := << Calculus`Integration`
In[2] := Integrate[UnitStep[-x] UnitStep[x], {x, -1, 1}]
Out[2] = 0
Best wishes,
Vladimir Bondarenko
Mathematical and Production Director
Symbolic Testing Group
http://www.CAS-testing.org/ GEMM Project (95% ready)
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