Services & Resources / Wolfram Forums
MathGroup Archive
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2007

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: question (for Mathematica 6!)

  • To: mathgroup at
  • Subject: [mg75581] Re: question (for Mathematica 6!)
  • From: dimitris <dimmechan at>
  • Date: Sat, 5 May 2007 06:12:11 -0400 (EDT)
  • References: <f1ept5$4n1$>

Yes I know these.

I just wonder why until now (5.2) we had for example

Integrate[DiracDelta[x], x]
D[%, x]


and now this has changed.

Anyway...thanks for you response.


"Owen, HL (Hywel)" <h.l.owen at> wrote:

HeavisideTheta[0] is undefined
UnitStep[0] gives 1

Their integrals are the same (for example from -1 to 1).

D[HeavisideTheta[x], x] is DiracDelta[x]
D[UnitStep[x], x] is (-1 - DiscreteDelta[x] + UnitStep[-x] +
UnitStep[x])/(1 -

=CF/=C7 dimitris =DD=E3=F1=E1=F8=E5:
> I don't have a copy of Mathematica 6 but having spent much time
> reading the online documentation (not only because of curiosity!) I
> have one question...
> Can somebody explain me the introduction of the HeavisideTheta
> function
> in version 6?
> Note that the UnitStep function is still here
> Dimitris

  • Prev by Date: Re: Integrating Differential Equations with Time Delay
  • Next by Date: Re: Creating boxes in text cells.
  • Previous by thread: Re: question (for Mathematica 6!)
  • Next by thread: Re: question (for Mathematica 6!)