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From: Hermann Peifer <peifer@gmx.eu>
Newsgroups: comp.graphics.apps.gnuplot
Subject: Re: Major and minor ticks artifact
Date: Sat, 15 Mar 2014 13:27:30 +0100
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On 2014-03-14 23:54, Janis Papanagnou wrote:
>
> As said, I used a workaround to adjust the png size so that the rounding
> issues - as far as I suspect - eliminate each other. (Still can't believe,
> though, that this is how such elementary problems are to be countered with
> gnuplot.)
>

I just looked into the source code of axis.c [1], I never did that 
before. As an outspoken non-programmer, I looked more into the comments 
than into the actual code. I hope that I was looking into the right 
piece of code in the first place.

Anyway, a programmer with initials "HBB" (no idea who this could be) 
seems to be well aware of FP issues, s/he uses floor() and ceil() to 
correct potential issues, but eventually states: "getting desperate...", 
etc. All these comments are 12 years old, as it looks like.

So there seems to be no real cure for the issue. IIRC, I occasionally 
defined a png size of something like 600,800.1 or some such to make 
similar issues go away. This is not very elegant and it basically means 
that I was "chasing the devil with the help of Beelzebub", as we say in 
German. But there seems to be little else that one can do.

Hermann

[1] 
http://gnuplot.cvs.sourceforge.net/viewvc/gnuplot/gnuplot/src/axis.c?revision=1.130&view=markup