Re: Plans for gnuplot version 5 [integer division]

[Jonathan T. <jt...@as...>]

On Thu, Apr 17, 2014 at 08:29:56PM +0000, Tait wrote:
> The root question is, what do gnuplot's users expect?
[[...]]
> I don't think most gnuplot users are familiar with C, so while
> gnuplot's mannerisms mirror C*, that's meaningless to many users.
> Users expect division to promote-to-float as necessary because all the
> other tools they are familiar with do it that way, from their paper
> and pencil to their calculator to WolframAlpha to R.

The problem is that we don't have any *data* on what "most gnuplot
users" expect, nor on "all the other tools they are familiar with".
We only have conjecture.

For some people "all the other tools" are software environments
(e.g., C, C++, Java, Perl, Python, Fortran, Pascal, PL/I, ...) where
integer division truncates.  For some (other) people "all the other
tools" are software environments (e.g., APL, R, pocket calculators,
spreadsheets) where integer division promotes the arguments to float.
The problem is that we don't know the relative sizes of these different
sets of gnuplot users.  Nor do we know what fraction of them have
existing scripts which would break if we changed the default.



This topic has been argued for a long time.  I think it might be useful
to revive an old suggestion from Dave Denholm:

> Date: Thu, 05 Aug 2004 17:50:43 +0100
> From: Dave Denholm <dde...@es...>
> Reply-To: gnu...@li...
> To: gnu...@li...
> Subject: Re: [Gnuplot-bugs] Interpretation of commandline numbers
> 
> I wonder if it is worth putting in special
> code to detect division of two integer constants, and warn once per
> session. (every evaluation would obviously be too often)

ciao,

-- 
-- "Jonathan Thornburg [remove -animal to reply]" <jt...@as...>
   Dept of Astronomy & IUCSS, Indiana University, Bloomington, Indiana, USA
   "There was of course no way of knowing whether you were being watched
    at any given moment.  How often, or on what system, the Thought Police
    plugged in on any individual wire was guesswork.  It was even conceivable
    that they watched everybody all the time."  -- George Orwell, "1984"