Re: [Gnuplot-bugs] Interpretation of commandline numbers

[Dave D. <dde...@es...>]

Reginald Beardsley <rb...@su...> writes:

>    In my view, this violates the principle of "least surprise". It
>    took me over an hour to figure out why things didn't plot where
>    I expected.
>
>    plot [x=0:10] x/3+13/3,x/3+13.0/3.0
>
>    I'm quite familiar w/ the rules for integer math, I just had no
>    reason to expect integer math rules in this context.
>

This crops up so often... 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)


Just a quick scan over the action table after parsing, to detect the
sequence  (puchc int), (pushc int), div

gnuplot> show at x/3.0 + 10/3 

        push x
        pushc 3.0
        div
        pushc 10
        pushc 3
        div
        plus


Or even - when appending the 'div' action, peek back at the previous
two entries.

This isn't going to catch the sequence

x=13
print x/3

but it might stop the user scratching their head for too long if they
then resort to typing in things like

  print 13/3


dd
-- 
Dave Denholm              <dde...@es...>       http://www.esmertec.com