Subject: plotting problem with trigonometric functions
From: Robert Dodier
Date: Wed, 14 Mar 2012 12:22:12 -0600
Looks like a Gnuplot bug to me.
This is enough to trigger it:
$ cat /tmp/baz.data
-1. 1.
0.7068965517241379 0.99999999999999989
1. 1.
then in gunplot, issue: plot "/tmp/baz.data"
$ gnuplot --version
gnuplot 4.4 patchlevel 2
I suppose Gnuplot is trying to find the range and getting
mixed up somehow. Incidentally if all y-values are exactly the
same it doesn't seem to have the same problem.
I guess somebody should forward this to the Gnuplot team
but I'm too lazy.
best
Robert Dodier
On 3/14/12, Raymond Toy <toy.raymond at gmail.com> wrote:
> On Wed, Mar 14, 2012 at 9:56 AM, Oliver Kullmann
> <O.Kullmann at swansea.ac.uk>wrote:
>
>> I can confirm that behaviour, using
>>
>> Maxima version: 5.26.0
>> Maxima build date: 1:35 12/20/2011
>> Host type: x86_64-unknown-linux-gnu
>> Lisp implementation type: ECL
>> Lisp implementation version: 11.1.1
>>
>> Plotting just sec(x) or cos(x) is not a problem,
>> but the product seems to run into an infinite loop.
>>
>
> Maxima hangs and not gnuplot?
>
> If so, try changing the adapt_depth plot_option to 1 or 0 and see if that
> helps.
>
> Ray
>