bug alert!
- To: mathgroup at smc.vnet.net
- Subject: [mg25301] bug alert!
- From: Jack Goldberg <jackgold at math.lsa.umich.edu>
- Date: Tue, 19 Sep 2000 03:45:22 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hi group:
Brief report of a bug: ver 4.0x on PowerMac and Unix systems.
Sum[ UnitStep[x-k],{k,0,Infinity} ] -> (1+x)*UnitStep[x]
which is incorrect. The correct answer is Floor[x]*UnitStep[x].
This error is compounded when you
Sum[f[x-k]*UnitStep[x-k],{k,0,Infinity}],
in that not only to you get an incorrect answer, the answer contains hidden
variables and is total nonsense.
Something is seriously at fault here.