Re: Unitstep

[Malte Boegershausen <malte@XXXXXXX.ch>]

Jens-Peer Kuska wrote:
> 
> Hmm,
> 
> Mathematica 4.1 sagt:
> 
> In[]:=FullSimplify[UnitStep[t], t > 0]
> Out[]= 1

Danke, das hilft.

aber:

In[]:=  FullSimplify[DiracDelta[x], x > 0]
Out[]:= DiracDelta[x]

und

In[]:=  FullSimplify[DiracDelta[x]x]
Out[]:= 0

In[]:=  FullSimplify[DiracDelta[x - y](x - y)]
Out[]:= (x - y) DiracDelta[x - y]

Malte

> 
> und
> 
> In[]:=FullSimplify[UnitStep[t], t === 1 || t === 2]
> 
> FullSimplify::"fas": "Warning: self-contradictory assumptions
> encountered."
> 
> Out[]= 1
> 
> Gruss
>   Jens
>