Re: Incredible slow Plot
- To: mathgroup at smc.vnet.net
- Subject: [mg120152] Re: Incredible slow Plot
- From: Peter Pein <petsie at dordos.net>
- Date: Sun, 10 Jul 2011 05:01:06 -0400 (EDT)
- References: <iv9etb$dg1$1@smc.vnet.net>
Am 09.07.2011 13:43, schrieb Iván Lazaro:
> Hi!
>
> I'm trying to Plot a result from NDSolve. The problem is that when I
> pass this solution to Plot it takes an incredible long time (four
> hours for times between 0 and 1200) to plot. I tried generating an
> image file (.jpg, .eps, etc.) but that doesn't change anything. I
> tried also giving to Plot the option PerformanceGoal -> "Speed", but
> it gives me only half an hour less of waiting time. The other options
> (like PlotPoints -> Number, MaxRecursion -> 0 ) give an improvement
> but the image is ugly unless PlotPoints is high, which at the end is
> the same.
>
> I tried also asking for Plot only the last 200 units of time, trying
> to avoid the most oscillating part of the graphic, but that really
> doesn't help (and really it's not what I need).
>
> Finally, the resulting InterpolatingFunction, when evaluated outside
> Plot, evaluates fast, and a ListPlot using points returned by a Table
> works well, but the resulting graphic is insanely big (35, 36 Mb) if I
> put the points necessary to give account of the features of the
> dynamic.
>
> Unfortunately I can't give you an example because the equations I'm
> solving are too long, but I wonder if there is someway to generate the
> graphic, either on the interface or in a file, to not be so slow.
>
> Thanks in advance, and sorry for this vague question (which, by the
> way, without examples, is useless... by I had to give it a try).
>
Hi,
did you try
sol=NDSolve[{eqns, cond},f,{t,0,1200}][[1]];
Plot[Evaluate[f[t]/.sol],{t,0,1200}]
?
Peter