Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2001

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Problem overriding simple built-in functions

  • To: mathgroup at smc.vnet.net
  • Subject: [mg28809] Re: Problem overriding simple built-in functions
  • From: "Orestis Vantzos" <atelesforos at hotmail.com>
  • Date: Mon, 14 May 2001 01:33:01 -0400 (EDT)
  • Organization: National Technical University of Athens, Greece
  • References: <9dld4j$o9b@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

GCD is a protected Symbol, so you can't add any new definitions.
Try Unprotect[GCD] first...and don't forget to Protect[GCD] after you make
the new assignment.
Orestis

"Jean-Christophe Deschamps" <jchd at worldnet.fr> wrote in message
news:9dld4j$o9b at smc.vnet.net...
> Hi,
>
> I'm told the following occurs under Mathematica v4.0:
>
> In[1]:= GCD[{3, 6}]
> Out[1]= {3, 6}
> In[2]:= GCD[x_List] := Apply[GCD, x]
> In[3]:= GCD[{3, 6}]
> Out[3]= GCD[{3, 6}]
> In[4]:= Apply[GCD, {3, 6}]
> Out[4]= 3
>
> Why is it so? It looks like the override is ignored, but why?
>
> The same exerpt seems to work fine under version 2.x.
>




  • Prev by Date: Re: Exponential Equations
  • Next by Date: Re: MATHEMATICA 4.0 - IWANT TO COPY DATA FROM OTHER APPLICATION
  • Previous by thread: Problem overriding simple built-in functions
  • Next by thread: Re: Problem overriding simple built-in functions