Re: Re: Bug Report - Two numerical values for a same variable
- To: mathgroup at smc.vnet.net
- Subject: [mg54336] Re: [mg54296] Re: Bug Report - Two numerical values for a same variable
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Thu, 17 Feb 2005 10:30:53 -0500 (EST)
- References: <cuhr4q$978$1@smc.vnet.net> <cukc65$lup$1@smc.vnet.net> <200502130521.AAA03676@smc.vnet.net> <opsl4914q7iz9bcq@monster> <002301c51217$ad7438b0$b5803e44@Dell> <cup6bc$e11$1@smc.vnet.net> <curp0c$qv3$1@smc.vnet.net> <200502161936.OAA19201@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
On 16 Feb 2005, at 20:36, Maxim wrote: > On Tue, 15 Feb 2005 03:06:52 +0000 (UTC), Carl K. Woll > <carlw at u.washington.edu> wrote: > >> >> Objects with head Rational are atoms, so you don't have access to the >> integers inside a rational object. It's the samething as complex >> numbers. >> For example, >> >> Complex[6,7] /. 7->1 >> 6 + 7 I >> >> Carl Woll >> > > However, if I construct something like Complex[E, E] manually, it > won't be > an atom, and some functions will have problems with it: > > In[1]:= > Complex[E, E] // Re // N > Complex[E, E] // Re // ComplexExpand // N > > Out[1]= > 2.7182818 > > Out[2]= > 2.7182818 + 2.7182818 I > > Perhaps this is an unallowed construct, but how am I supposed to know > that > it's unallowed? > > Maxim Rytin > m.r at inbox.ru > Well, you can check that In[16]:= Complex[E, E] == E + I*E Out[16]= Complex[E, E] == (1 + I)*E in other words, these two expressions are not considered equal. Even more obviously Rational[Pi,Pi] does not return 1. In general it is certainly true in the case of Mathematica that you can't conclude from the fact that there is no explicit statement saying that something is not allowed that it will be all right to do it. Rather like in real life, I would say. Andrzej Kozlowski Chiba, Japan http://www.akikoz.net/andrzej/index.html http://www.mimuw.edu.pl/~akoz/
- References:
- Re: [Mathematica 5.1] Bug Report - Two numerical values for a same variable
- From: "David W. Cantrell" <DWCantrell@sigmaxi.org>
- Re: Bug Report - Two numerical values for a same variable
- From: Maxim <ab_def@prontomail.com>
- Re: [Mathematica 5.1] Bug Report - Two numerical values for a same variable