Services & ResourcesWolfram ForumsMathGroup Archive

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

Re: RE: Re: Sometimes <space> means multiple

• To: mathgroup at smc.vnet.net
• Subject: [mg75423] Re: [mg75364] RE: [mg75358] Re: Sometimes <space> means multiple
• From: Murray Eisenberg <murray at math.umass.edu>
• Date: Sun, 29 Apr 2007 03:14:26 -0400 (EDT)
• Organization: Mathematics & Statistics, Univ. of Mass./Amherst
• References: <200704270918.FAA23598@smc.vnet.net>
• Reply-to: murray at math.umass.edu

Why "mistake"?  Why not allow Mathematica to mimic as much of 
traditional mathematical notation as possible without running into 
genuine ambiguity?

After all, it's really convenient to be able to use 2 Exp[x] and Cos[2 
t] -- and even 2Exp[x] and Cos[2t] -- without having to insert an extra, 
distracting multiplication symbol.  Then the usage in 2 4, for example, 
just extends that.

In my own work, I ordinarily include an explicit multiplication symbol 
-- and I prefer the multiplication sign one gets from Esc * Esc instead 
of the FORTRANish * -- when the factors are numbers.  There's nothing to 
prevent you from doing that if you don't like the implicit 
multiplication indicated by a space.


Virgilio, Vincent - SSD wrote:
> Personally, I think it was a mistake to overload the meaning of "space"
> to multiply. I bet Wolfram Inc. would reverse that decision now, if it
> wasn't for backward compatibility.
> 
> I like to compare Mathematica to C++. Somewhere in his writings, Bjarne
> Stroustrup mentions the same issue, and his decision not to overload
> whitespace. I think the question also arises on the Boost mailing lists
> now and then, mostly tongue-in-cheek.
> 
> (Corrections welcome.)
> 
> Vince Virgilio
> 
> -----Original Message-----
> From: Bill Rowe [mailto:readnewsciv at sbcglobal.net]
> Sent: Thursday, April 26, 2007 3:35 AM
> To: mathgroup at smc.vnet.net
> Subject: [mg75364] [mg75358] Re: Sometimes <space> means multiple , sometimes not
> 
> On 4/25/07 at 5:27 AM, siewsk at bp.com wrote:
> 
>> As a newbie, I was taught that <space> character in Mathematica means
>> multiple. But sometimes it does not.
> 
>> For example:
> 
> <examples snipped>
> 
> Mathematica allows spaces to be placed before or after any operation.
> Consequently, a space is only interpreted as a multiply when there is no
> other operator or other possible interpretation.
> 
> So, -4 -2 is the same as -4 - 2 or -4-2 and gives -6 but
>      -4 (-2) will yield 8
> --
> To reply via email subtract one hundred and four
> 
> *****************************************************************
> This e-mail and any files transmitted with it may be proprietary =
> 
> and are intended solely for the use of the individual or entity to =
> 
> whom they are addressed. If you have received this e-mail in =
> 
> error please notify the sender. Please note that any views or
> opinions presented in this e-mail are solely those of the author =
> 
> and do not necessarily represent those of ITT Corporation. The =
> 
> recipient should check this e-mail and any attachments for the =
> 
> presence of viruses. ITT accepts no liability for any damage =
> 
> caused by any virus transmitted by this e-mail.
> *******************************************************************
> =0D
> 

-- 
Murray Eisenberg                     murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower      phone 413 549-1020 (H)
University of Massachusetts                413 545-2859 (W)
710 North Pleasant Street            fax   413 545-1801
Amherst, MA 01003-9305

• Follow-Ups:
  • Re: Re: RE: Re: Sometimes <space> means multiple
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>

• References:
  • RE: Re: Sometimes <space> means multiple , sometimes not
    • From: "Virgilio, Vincent - SSD" <Vincent.Virgilio@itt.com>