Re: Using subscripts in variable _names_!!!
- To: mathgroup at smc.vnet.net
- Subject: [mg6169] Re: [mg6143] Using subscripts in variable _names_!!!
- From: Allan Hayes <hay at haystack.demon.co.uk>
- Date: Thu, 27 Feb 1997 02:52:12 -0500
- Sender: owner-wri-mathgroup at wolfram.com
w.meeussen" <w.meeussen at solair4b.eunet.be>
[mg6143] Re: [mg6136] Re: [mg6104] Using subscripts in variable
_names_!!!
writes
>define functions f[1][x], f[2][x], ...
> Array[f[#][x]&,5]
>give x an Integer value 7,
> %/.x->7
>now make the functions to go numeric
> %//N
>and you end up with your indices going to Reals too:
> {f[1.][7.],f[2.][7.],f[3.][7.],f[4.][7.],f[5.][7.]}
>somehow, it seems clear that the indices were supposed to be
Integer >'type'
Wouter,
The attributes NHoldAll, NHoldFirst, NHoldRest prevent N acting:
SetAttributes[f,NHoldAll]
Array[f[#][x]&,5];
%/.x->7;
%//N
{f[1][7.], f[2][7.], f[3][7.], f[4][7.], f[5][7.]}
Allan Hayes,
hay at haystack.demon.co.uk
http://haystack.demon.co.uk