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Re: Bug in Graphics output of Circle primitive?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg62903] Re: [mg62860] Bug in Graphics output of Circle primitive?
  • From: pantagruel123 at aol.com
  • Date: Thu, 8 Dec 2005 00:04:40 -0500 (EST)
  • References: <200512070410.XAA23753@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Try changing the plot range to something like
PlotRange -> {{0,0.004}, Automatic}

Then the arc goes right though the origin.  So the problem seems to be with=
the way it labels the axes rather than how the arc is mapped into the coordi=
nate system. 

C. Arthur

-----Original Message-----
From: Yves Klett <yk at despammed.com>
To: mathgroup at smc.vnet.net
Subject: [mg62903] [mg62860] Bug in Graphics output of Circle primitive?


Dear Mathgroup,

I stumbled upon a strange (and suspicious) graphics output when
displaying arcs with small angular length.

If I evaluate the following lines:

r = 10000;
gx = Circle[{r, 0}, r, {179=B0, 180=B0}];
Show[Graphics[{gx, Point[{0, 0}]}], Axes -> True,
  PlotRange -> {Automatic, Automatic}, AxesOrigin -> {0, 0}];

(or the same in plain text format...)

r=10000;
gx=Circle[{r,0},r,{179\[Degree],180\[Degree]}];
Show[Graphics[{gx,Point[{0,0}]}],Axes\[Rule]True,
     PlotRange\[Rule]{Automatic,Automatic},AxesOrigin\[Rule]{0,0}];


I get the point as specified at the origin {0,0}. The arc though does
not intersect at the origin as it should IMHO, but somewhat left of it.
  Same thing occurs for arbitrary values of r.

There might be some precision problem of the postscript output
concerning the Circle primitive when very different axes scaling is
used, but any enlightment would be appreciated.

I am using V5.2 on windows. Any hints or tips to get rid of this faulty
output would be very welcome,

Yves Klett



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