Re: Attributes
- To: mathgroup at smc.vnet.net
- Subject: [mg6449] Re: Attributes
- From: Dick Zacher <dick at loc3.tandem.com>
- Date: Fri, 21 Mar 1997 22:59:49 -0500 (EST)
- Organization: Tandem Computers
- Sender: owner-wri-mathgroup at wolfram.com
Marlies Brinksma wrote: > > When removing the attribute Orderless of the function Times > > (ClearAttributes[Times, Orderless]), this attribute disappears (which is > > its normal behaviour;-), but reappears(!) after a function-call of a funtion I > > defined. I checked this function thouroughly, but I cannot find any relation > > to Times. > > I performed some tests and now I know that the feature I described is due to > the function TableForm. So probably this function has some kind of a side > effect related to Times? Does anyone know more about this? Interesting. The attributes only got restored the first time I invoked TableForm. So If I invoke TableForm first, then clear the attribute, then invoke TableForm more times, the attributes stay cleared. I'm curious as to what is happening, even though I don't think I would choose to write code that depends on clearing the Orderless attribute of Times. That is not to say that I wouldn't ever change the attributes of built-in functions. I used to routinely change the HoldAll attribute of If to HoldRest in version 2.2; in version 3.0 one doesn't have to do that any more! -- ----------------------------- Dick Zacher Performance Engineering Dept., Tandem Computers zacher_dick at tandem.com phone: 408-285-5746 fax: 408-285-7079