Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2003
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2003

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: ParametricPlot - a feature or a bug?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg39469] Re: [mg39447] ParametricPlot - a feature or a bug?
  • From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
  • Date: Mon, 17 Feb 2003 04:34:58 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

Here is another easy fix for the problem. I doubt however that it woudl 
be useful to try to make it a built-in feature of ParametricPlot:



Show[ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 5000*Pi}, AspectRatio -> 
Automatic,
     DisplayFunction -> Identity] /. Line[l_List] :> Line[Sort[l, 
Arg[Complex @@ #1] <= Arg[Complex @@ #2] & ]],
   DisplayFunction -> $DisplayFunction]



On Sunday, February 16, 2003, at 10:34 PM, Andrzej Kozlowski wrote:

> Essentially the same thing has been mentioned on this list a lot of 
> times. You need to either set PlotPoints manually, e.g.
>
> ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 500 Pi}, AspectRatio -> 
> Automatic,
>        PlotPoints -> 500];
> or you can set PlotDivision to a larger value
>
> ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 500 Pi}, AspectRatio -> 
> Automatic,
>        PlotDivision -> 500];
>
>
> or you can just use ListPlot, even with quite large step size:
>
> ListPlot[Table[{Cos[t], Sin[t]}, {t, 0, 500 Pi,
>       1}], AspectRatio -> Automatic]
>
>
> The fact that other systems may not need the above adjustment need not 
> at all mean that there is a bug in Mathematica or that they do this 
> sort of thing better in general. To say that you would have to 
> carefully examine how they avoid this problem and  at what price (if 
> any). After all, ListPlot which does not do any adaptive sampling does 
> not have this problem yet it certainly is not superior, in general, to 
> ParametricPlot as a plotting tool.
>
> Andrzej Kozlowski
> Yokohama, Japan
> http://www.mimuw.edu.pl/~akoz/
> http://platon.c.u-tokyo.ac.jp/andrzej/
>
>
> On Sunday, February 16, 2003, at 08:13 PM, Vladimir Bondarenko wrote:
>
>> Hello,
>>
>> While trying to plot complex parametric plots with large values
>> of the parameter I run into a problem which boils down to the
>> following simple observation.
>>
>> a) ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 1 Pi}, AspectRatio -> 
>> Automatic];
>>
>>      A perfect circumference.
>>
>> b) ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 200 Pi}, AspectRatio -> 
>> Automatic];
>>
>>      Instead of a circumference, not a very wide annulus.
>>
>> c) ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 500 Pi}, AspectRatio -> 
>> Automatic];
>>
>>      An annulus which width is equal to the radius of the inner
>>      circumference.
>>
>> d) ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 1000 Pi}, AspectRatio -> 
>> Automatic];
>>
>>      A black ring with tiny white spots.
>>
>> e) ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 10^19 Pi}, AspectRatio -> 
>> Automatic];
>>
>>      A funny net.
>>
>> f) ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 10^20 Pi}, AspectRatio -> 
>> Automatic];
>>
>>      A segment.
>>
>> g) ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 10^26 Pi}, AspectRatio -> 
>> Automatic];
>>
>>      Only the axes are shown. There is no graph itself.
>>
>>
>> Is (at least a part of the shown output) a feature or a bug?
>>
>> (By the way, before answering why do not try to solve the same
>> problems with a couple of other systems? ;-)
>>
>>
>> Best wishes,
>>
>> Vladimir Bondarenko
>> Mathematical and Production Director
>> Symbolic Testing Group
>>
>> Web  :  No other my site is permitted to me to quote here
>>         http://www.CAS-testing.org/  GEMM Project (95% ready)
>>
>> Email:  vvb at mail.strace.net
>> Voice:  (380)-652-447325 Mon-Fri 6 a.m. - 3 p.m. GMT
>> ICQ  :  173050619
>> Mail :  76 Zalesskaya Str, Simferopol, Crimea, Ukraine
>>
>>
>>
>>
>>
>
>
Andrzej Kozlowski
Yokohama, Japan
http://www.mimuw.edu.pl/~akoz/
http://platon.c.u-tokyo.ac.jp/andrzej/



  • Prev by Date: RE: ParametricPlot - a feature or a bug?
  • Next by Date: RE: Re: Problem with If statement in a Do or a While loop
  • Previous by thread: RE: ParametricPlot - a feature or a bug?
  • Next by thread: Simplify a module