Re: math =!= mathematica
- To: mathgroup at smc.vnet.net
- Subject: [mg108605] Re: math =!= mathematica
- From: dh <dh at metrohm.com>
- Date: Thu, 25 Mar 2010 04:24:11 -0500 (EST)
- References: <hoa19m$fdk$1@smc.vnet.net>
Hi Ralf, if you say: `Array[c,3]=17 you are not calling the function "Array" that lives in the System context, but you create a new symbol in the context "A". Hardly what you want. Daniel On 23.03.2010 10:23, hemmecke wrote: > Does somebody know why I get different behaviour for the following > commands in a commandline session of mathematica 7 or inside a notebook? > It also seems to be different in different Mathematica versions for the > notebook format. > See http://www.risc.jku.at/people/hemmecke/mathematica/ for the > notebook files for Mathematica 5.2, 6.0, 7.0. > > Can someone explain the > > General::dupsym: The symbol Array with context A` already exists. > > message? Why does that message appear at all? If A`Array exists, then > Mathematica should just use it, shouldn't it? > > According to http://reference.wolfram.com/mathematica/tutorial/Contexts.html > we have: > `name a symbol in the current context > So why is Mathematica complaining? > > Ralf > >> math > Mathematica 7.0 for Linux x86 (32-bit) > Copyright 1988-2008 Wolfram Research, Inc. > > In[1]:= BeginPackage["A`"] > > Out[1]= A` > > In[2]:= {$ContextPath, $Context} > > Out[2]= {{A`, System`}, A`} > > In[3]:= `Array[c,3]=17 > > Array::shdw: Symbol Array appears in multiple contexts {A`, System`} > ; definitions in context A` may shadow or be shadowed by other > definitions. > > Out[3]= 17 > > In[4]:= Array[c,3] > > Out[4]= 17 > > In[5]:= `Array[c,3] > > General::dupsym: The symbol Array with context A` already exists. > > Out[5]= Removed[Array][c, 3] > > In[6]:= A`Array[c,3] > > Out[6]= 17 > -- Daniel Huber Metrohm Ltd. Oberdorfstr. 68 CH-9100 Herisau Tel. +41 71 353 8585, Fax +41 71 353 8907 E-Mail:<mailto:dh at metrohm.com> Internet:<http://www.metrohm.com>