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Re: How does 'arc' work?

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luser- -droog <mijoryx@yahoo.com> writes:

> On Sunday, April 3, 2016 at 9:40:55 AM UTC-5, Scott Hemphill wrote:
>  
>> For real PostScript?  Feed this to your printer.  Modify it as desired.
>> 
>> ========================================================================
>> %!PS
>> 
>> % What is the distance of an inner Bezier curve control point to the outer
>> % point as a function of angle in an "arc" operator
>> 
>> /dist
>> {
>>   /angle exch def
>>   gsave
>>     newpath
>>     0 0 1000 0 angle arc
>>     {pop pop} {pop pop} {pop pop pop pop exch pop} {} pathforall
>>   grestore
>>   1000 div
>> }
>> bind def
>> 
>> /tmpstr 20 string def
>> 
>> % I use paper size "letter"
>> 
>> /in { 72 mul } bind def
>> /Times-Roman findfont 10 scalefont setfont
>> /lineskip 12 def
>> /nl { 1 in y moveto /y y lineskip sub def } bind def
>> /y 10 in def
>> nl
>> 
>> 10 10 90 { dup tmpstr cvs show (  ) show dist tmpstr cvs show nl } for
>> 
>> showpage
>> ========================================================================
>> 
>
> Very cool. There may indeed be something wrong with my implementation.
>
> gs gives:
> 10 0.0582147
> 20 0.11665
> 30 0.175536
> 40 0.235099
> 50 0.295591
> 60 0.357264
> 70 0.420398
> 80 0.485293
> 90 0.552282
>
> whereas xpost gives:
> 10 0.115506
> 20 0.231321
> 30 0.346987
> 40 0.461987
> 50 0.575741
> 60 0.687515
> 70 0.796415
> 80 0.901347
> 90 1.000998

I changed the above program to make an arc with radius 1024 instead of
1000 so that presumably the processor can do the division with no
additional roundoff error.

My HP LaserJet Pro M452dw gives:

10 0.0582143
20 0.116652
30 0.175537
40 0.235103
50 0.295593
60 0.357266
70 0.420398
80 0.485294
90 0.55228

There is something funky going on with small radii, which is why I used
a larger radius to begin with.  If I change the radius from 1024 to 1, I
get this:

10 0.0582886
20 0.116699
30 0.175537
40 0.235107
50 0.295593
60 0.357239
70 0.42041
80 0.485291
90 0.552307

Scott
-- 
Scott Hemphill	hemphill@alumni.caltech.edu
"This isn't flying.  This is falling, with style."  -- Buzz Lightyear

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Thread

How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2013-11-20 23:23 -0800
  Re: How does 'arc' work? bugbear <bugbear@trim_papermule.co.uk_trim> - 2013-11-21 14:05 +0000
    Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2013-12-01 04:03 -0800
  Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2013-11-23 15:06 -0800
    Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2013-12-01 03:48 -0800
      Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2013-12-01 03:58 -0800
        Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2013-12-10 23:02 -0800
          Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2013-12-11 00:17 -0800
            Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2013-12-11 00:20 -0800
              Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2013-12-11 01:37 -0800
              Re: How does 'arc' work? tlvp <mPiOsUcB.EtLlLvEp@att.net> - 2014-02-28 03:47 -0500
                Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2014-03-01 00:30 -0800
          Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2014-04-29 13:10 -0700
    Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2019-02-02 16:19 -0800
  Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2014-05-02 06:29 -0700
    Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2014-05-08 02:21 -0700
      Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2016-04-01 15:28 -0700
        Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-04-02 21:35 -0700
          Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2016-04-03 13:54 -0700
            Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-04-18 21:40 -0700
              Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-04-19 15:04 -0700
                Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2016-04-20 02:06 -0700
                Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2016-04-20 05:18 -0700
                Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-04-22 00:40 -0700
                Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-04-22 11:32 -0700
                Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-04-23 20:49 -0700
                Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-04-23 22:46 -0700
                Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2016-04-24 04:01 -0700
                Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-04-30 21:47 -0700
                Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-05-01 02:59 -0700
        Re: How does 'arc' work? Scott Hemphill <hemphill@hemphills.net> - 2016-04-03 10:40 -0400
          Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-04-05 21:48 -0700
            Re: How does 'arc' work? Scott Hemphill <hemphill@hemphills.net> - 2016-04-06 10:37 -0400
            Re: How does 'arc' work? luser- -droog <mijoryx@yahoo.com> - 2016-04-07 23:59 -0700
            Re: How does 'arc' work? jdaw1 <jdawiseman@gmail.com> - 2016-04-19 02:54 -0700

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