Fwd: [Maxima] still having plotting problem

[Robert D. <rob...@gm...>]

Take 2 -- I've now subscribed to gnuplot-beta ...

Some additional info from Joaquin: he patched axis.c as suggested and
the observed result is endless repetitions of

gen_tics: top of loop; start=1.000000e+00, end=1.000000e+00,
step=1.110223e-16, tic=1.000000e+00

which shows that Gnuplot is indeed stuck in the loop in axis.c.

Thanks for any light you can shed on this.

Robert Dodier


---------- Forwarded message ----------
From: Robert Dodier <rob...@gm...>
Date: Sat, 17 Mar 2012 14:27:19 -0600
Subject: Fwd: [Maxima] still having plotting problem
To: gnu...@li..., ult...@gm...

Joaquin, thanks for the GDB output.

Looking at gnuplot/src/axis.c, I see that the call to gprintf
is within a loop which won't terminate if end + step == end
or step + end == step (this is possible for very small values of step).

In order to verify whether that is actually happening, can you
apply the attached patch (axis.c-patch) and try
plot "maxout.gnuplot_pipes" in gnuplot again?

If all is well, you should get a small number of output lines
and then a plot. If it's actually stuck in that loop, you'll get unending
output. Let us know how it plays out.

best

Robert Dodier

PS to Gnuplot developers: Maxima generated maxout.gnuplot_pipes
and then called Gnuplot to plot it. Gnuplot gets stuck.
gdb_output.txt shows a stack trace. Gnuplot was pulled from CVS
and compiled on a Ubuntu 10.10 or 11.10 system (I forget which)
with x86_64 cpu if I remember correctly. When I try the same thing on
my system (Gnuplot CVS on Ubuntu 8.04 on x86),
the data are successfully plotted.

---------- Forwarded message ----------
From: joaquin borges <ult...@gm...>
Date: Sat, 17 Mar 2012 14:15:25 -0300
Subject: Re: [Maxima] still having plotting problem
To: Robert Dodier <rob...@gm...>

On 03/17/2012 02:37 AM, Robert Dodier wrote:
> Thanks for sending maxout.gnuplot_pipes.
> When I run gnuplot (4.7 from cvs) it successfully plots the data.
> So it's hard to figure out what's going on.
>
> One idea: can you run Gnuplot within gdb (debugger).
> If the installed binary has been stripped of symbols,
> try running the one from the build directory. e.g.
>
> $ cd<whatever>/gnuplot
> $ gdb src/gnuplot
> <now try the offending data file>
>
> When Gnuplot seems to wait forever, hit control-C
> and then enter the command "where" in gdb.
> It should give you a stack trace.
>
> best
>
> Robert Dodier
>
Thanks for your reply .
The output of gdb  is attached
best
joaquin