Re: Integrate with If
- To: mathgroup at smc.vnet.net
- Subject: [mg22197] Re: [mg22180] Integrate with If
- From: Hartmut Wolf <hwolf at debis.com>
- Date: Fri, 18 Feb 2000 02:34:34 -0500 (EST)
- Organization: debis Systemhaus
- References: <200002170624.BAA04409@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Johan Berglind,5879 schrieb:
>
> Why does
>
> Integrate[If[Sin[t] > 0, 1, 0] , {t, -Pi, Pi}]
>
> evaluate to 2Pi?
>
> Plot[If[Sin[t] > 0, 1, 0] , {t, -Pi, Pi} ]
>
> looks all right.
>
> Puzzled,
>
> Johan Berglind,
> Chalmers, Goteborg,
> Sweden.
Dear Johan,
Integrate doesn't work with If, use UnitStep instead. So both
In[17]:= Plot[UnitStep[t], {t, -Pi, Pi}]
Out[17]= Graphics[]
In[18]:= Integrate[UnitStep[t], {t, -Pi, Pi}]
Out[18]= Pi
do well.
Kind regards, Hartmut
- References:
- Integrate with If
- From: "Johan Berglind,5879" <johanbe@chl.chalmers.se>
- Integrate with If