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From: Christian Schlauer <cs-muelleimer-rubbish.bin@arcor.de>
To: emacs-devel@gnu.org
Subject: Re: Calc: `*' binds more strongly than `/'
Date: Wed, 18 Apr 2007 23:29:55 +0200	[thread overview]
Message-ID: <878xcpz7zg.fsf@totally-fudged-out-message-id> (raw)
In-Reply-To: 867isb2mnv.fsf@blue.stonehenge.com

merlyn@stonehenge.com (Randal L. Schwartz) writes:

>>>>>> "Christian" == Christian Schlauer
>>>>>> <cs-muelleimer-rubbish.bin@arcor.de> writes:
>
> Christian> I believe (but I do not know) that Calc's behaviour is
> Christian> (too) far from what `ordinary' people (like me ;-) would
> Christian> expect: I ran into this feature in my first table and
> Christian> wondered what was going on. I thought that Org-mode
> Christian> calculates `wrong'.
>
> You mean from what *programmers* think. Keep in mind that Calc was
> designed by a mathematician, and it's much more natural in math to
> have * have higher precedence than /. There's no promise that the
> order of operations is like programmer-think. I got used to it quite
> quickly when I was playing with Calc during its initial development.

Hm. I'm an engineer, not a programmer ;-) I can only say that Calc
seems to be a fantastic tool, especially when one is on a computer
where the `heaviest' math tool installed is some spreadsheet.

But I wouldn't recommend it to an engineer as it doesn't work in the
way I (and spreadsheet-users) am used to, that is left-to-right
evaluation in absence of parentheses.

I didn't think that my expectation of the order of operations is like
programmers think. I learned in school that when I write on paper

2 * 3
-----
4 * 5

I have to enter it in my pocket calculator (Casio) as 2*3/(4*5), and
it seems that Jay found the same behaviour with other brands. So it
starts with the school kids, not with programmers.

> I suggest it not be changed. It will break old code (Calc has been
> around for almost two decades)

That's the risk. I'm surprised: am I the first one to complain about
this feature? In 20 years? But then, Calc hasn't been bundled with
Emacs until now.

> it's a minor thing

I don't agree. When I write a formula for a table in Org-mode, I
always have to check it carefully as Calc does not work like Gnumeric,
Openoffice's spreadsheet, MATLAB, Excel, ... I simply have a bad
feeling when typing the formula due to this feature and the fact that
it makes using Calc more error-prone for me (and for all those
familiar with the spreadsheet programs mentioned before).

> and people have eventually stumbled on it, and it's well (over?)
> documented.

It is well-documented, but it is an unnecessary trap, IMO.

Regards,

Christian Schlauer

      reply	other threads:[~2007-04-18 21:29 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-14 11:57 Calc: `*' binds more strongly than `/' Christian Schlauer
2007-04-14 15:09 ` Jay Belanger
2007-04-15 19:21   ` Chong Yidong
2007-04-15 20:05     ` Stefan Monnier
2007-04-17 12:47       ` Randal L. Schwartz
2007-04-17 18:03         ` Stefan Monnier
2007-04-18  8:44           ` Kim F. Storm
2007-04-18 19:27             ` Stefan Monnier
2007-04-18 20:02               ` Davis Herring
2007-04-18 20:16                 ` David Kastrup
2007-04-18 21:43                   ` Davis Herring
2007-04-19 16:10                 ` Stefan Monnier
2007-04-20 11:13                   ` Randal L. Schwartz
2007-04-20 13:40                     ` Stefan Monnier
2007-04-20 14:07                       ` Jay Belanger
2007-04-22  1:31                         ` Miles Bader
2007-04-22 10:19                           ` Christian Schlauer
2007-04-22 10:23                         ` Christian Schlauer
2007-04-22 19:47                           ` Jay Belanger
2007-04-23 10:46                           ` Jason Rumney
2007-04-23 13:03                             ` Kim F. Storm
2007-04-23 15:54                               ` Jay Belanger
2007-04-25 19:56                                 ` Christian Schlauer
2007-04-25 20:54                                   ` Jay Belanger
2007-04-26  3:35                                     ` Stefan Monnier
2007-04-26  4:06                                       ` Jay Belanger
2007-04-26 14:11                                         ` Stefan Monnier
2007-04-26 21:07                                           ` Christian Schlauer
2007-04-26 15:07                                         ` Davis Herring
2007-04-26 16:01                                           ` Stefan Monnier
2007-04-26 18:32                                             ` Luc Teirlinck
2007-04-26 21:29                                               ` Christian Schlauer
2007-04-26 23:17                                                 ` Luc Teirlinck
2007-04-26 21:07                                     ` Christian Schlauer
2007-04-27  1:27                                       ` Jay Belanger
2007-04-26 17:47                                   ` Davis Herring
2007-06-20 15:23                         ` Jay Belanger
2007-06-20 16:02                           ` Kim F. Storm
2007-06-20 17:13                             ` Jay Belanger
2007-06-20 17:29                             ` Luc Teirlinck
2007-06-20 17:54                               ` Jay Belanger
2007-06-20 19:14                                 ` Kim F. Storm
2007-06-20 19:28                                 ` Luc Teirlinck
2007-06-20 20:18                                   ` Jay Belanger
2007-04-17 18:54         ` Jay Belanger
2007-04-18 21:55           ` Christian Schlauer
2007-04-19  2:58             ` Daniel Brockman
2007-04-22 10:27               ` Christian Schlauer
2007-04-26 16:00                 ` Daniel Brockman
2007-04-19 15:16           ` Drew Adams
2007-04-19 17:05             ` David Kastrup
2007-04-19 17:18               ` Drew Adams
2007-04-19 17:33                 ` David Kastrup
2007-04-16 15:38     ` Richard Stallman
2007-04-17 12:47 ` Randal L. Schwartz
2007-04-18 21:29   ` Christian Schlauer [this message]

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