Re: something like dB
- To: mathgroup at smc.vnet.net
- Subject: [mg56550] Re: something like dB
- From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
- Date: Fri, 29 Apr 2005 03:19:47 -0400 (EDT)
- Organization: Uni Leipzig
- References: <d4q0rb$o8i$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, HoldForm[0*dB] ?? Regards Jens "Zhengji Li" <zhengji.li at gmail.com> schrieb im Newsbeitrag news:d4q0rb$o8i$1 at smc.vnet.net... > Dear Mathematica ers, > > In engineering, we always like values such as > power be represented > in dB form. > I can make dB as a Unit, but things go to > strange when 0 dB occurs: > > Times[0, dB] will give 0 no matter dB is > ReadProtected or not. > > I have tried to define a upvalue for dB: > > dB /: Times[0, dB] = 1; but > Mathematica do not allow > this cause dB is not a > "function". > > I can define a new rule for Times: Times[0, > dB] = 1, but this may > slow down the > kernel. Anybody know how ? > > Best regards. >