Re: Problems with With/Block/Module functions
- To: mathgroup at smc.vnet.net
- Subject: [mg64269] Re: Problems with With/Block/Module functions
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Wed, 8 Feb 2006 06:29:53 -0500 (EST)
- Organization: The Open University, Milton Keynes, UK
- References: <dsccna$pae$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Mukhtar Bekkali wrote:
> Hi:
>
> I want to use local assignment done for a subscripted variable, where
> x1 is ought to be read as x subscript 1, and evaluate at local values
> function g[x1] and use the result later on. My code (not actual, just
> an example) is as follows:
>
> x1=0;
> With[{x1=1},y=g[x1]] (* is some specific arbitrary function, say x1^2
> *)
> y
>
> My error message is "Local variable specification {x1=0} contains x1=0
> which is an assignment to x1; only assignments to symbols are allowed"
> Where on earth does Mathematica see a function in x1. To me this is
> just a symbol. Please advise on a workaround. Thanks.
>
Hi Mukhtar,
You must use the command Symbolize (from the palette) from the package
Notation to transform x_1 in a symbol. See
http://documents.wolfram.com/mathematica/Demos/Notations/Functions/NotationDefinitionSymbolize.html
In[1]:=
Needs["Utilities`Notation`"]
In[2]:=
Symbolize[NotationBoxTag[\(x\_1\)]]
In[3]:=
x\[UnderBracket]Subscript\[UnderBracket]1 = 0;
With[{x\[UnderBracket]Subscript\[UnderBracket]1 = 1}, y =
g[x\[UnderBracket]Subscript\[UnderBracket]1]]
Out[4]=
g[1]
Best regards,
/J.M.