Integrating DiracDelta to get UnitStep
- To: mathgroup at smc.vnet.net
- Subject: [mg91238] Integrating DiracDelta to get UnitStep
- From: CRC <crobc at this-is-bogus.sbcglobal.net>
- Date: Mon, 11 Aug 2008 06:05:32 -0400 (EDT)
Hi:
I am a bit confused by Mathematica 6.0.3 behavior. I expect that:
In[n]:= Integrate[DiracDelta[x], {x, -\[Infinity], t},
Assumptions -> Im[t] == 0]
Will produce:
Out[n]= UnitStep[t]
But instead it produces:
Out[n]= 1
However,
In[n+1]:= Plot[ Integrate[DiracDelta[x], {x, -\[Infinity], t},
Assumptions -> Im[t] == 0], {t, -2, 2} ]
produces the expected plot of UnitStep[t].
Why doesn't the integration output the UnitStep function?
Thanks for input.
--
_____________________
CRC
crobc at REMOVE-THIS.sbcglobal.net
SuSE 10.3 Linux 2.6.22.17