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From: amason@cs.uct.ac.za (Ashton Mason)
Newsgroups: sci.fractals
Subject: Organics.par revisited - periodicity errors
Date: 31 Jul 1995 14:03:58 GMT
Organization: University of Cape Town
Lines: 94
Message-ID: <3vinse$s92@ucthpx.uct.ac.za>
NNTP-Posting-Host: ika.cs.uct.ac.za
 
Last week sometime, I posted a parameter file called organics.par, which
contained examples of things that occur in the M-Set which I call
organics. Ray Girvan suggested that they resembled the entire shape of
certain Julia sets, so I decided to examine the Julia sets corresponding
to the points in the M-Set where organics occur, to see whether these were
particularly remarkable.
 
I found that the Julia sets at these points generally resemble the
terrain in which the organics occur, with organic type parts of their
own. In general, the structure was very similar to the structure of the
Mandelbrot set in the corresponding position, which is not surprising.
 
However, I did find that Fractint is very prone to producing errors in
the organic parts of these Julias, as the images in this parameter file
show. After experimenting with various options, I came to the conclusion
that the errors were caused by periodicity checking. Turing periodicity
checking off solved the problem. I also noticed that the errors occured
to a much greater extent when floating point was turned on, but still
occured occasionally with integer math.
 
Are these errors common knowledge? Or am I doing something weird?
 
Ash
 
 
errors.par
----
 
30079501           { ;
  reset=1920 type=julia passes=2
  corners=-0.078610316118936083/0.021245683881063925/0.00609470981/0.08098\
  67098 params=0.4435773612284803/0.3721775378783693 float=y
  maxiter=65536 inside=0
  colors=000N_i<15>ffAhg8ig6kh3kh4<39>qBhrAjqBh<17>iRKiRJgPL<10>REbPDdOEc<\
  17>0dG<16>pk0<8>bc8`b9ZaB<5>NVLLUNISPFQR<4>9IQ8GQ8FQ<4>BAMC9LF8K<12>n65<\
  22>LIH<26>zfz<19>DXz<6>M_k
  }
 
30079502           { ;
  reset=1920 type=julia passes=1 corners=-2/2/-1.5/1.5
  params=0.4435773568133786/0.372177545877456 float=y maxiter=10000000
  inside=0
  colors=000N_i<15>ffAhg8ig6kh3kh4<39>qBhrAjqBh<17>iRKiRJgPL<10>REbPDdOEc<\
  17>0dG<16>pk0<8>bc8`b9ZaB<5>NVLLUNISPFQR<4>9IQ8GQ8FQ<4>BAMC9LF8K<12>n65<\
  22>LIH<26>zfz<19>DXz<6>M_k
  }
 
30079503           { ; try zooming into the 'lakes'
  reset=1920 type=julia passes=1 corners=-0.172/0.172/-0.129/0.129
  params=0.4435773568133786/0.372177545877456 float=y maxiter=1000000
  inside=0
  colors=000N_i<15>ffAhg8ig6kh3kh4<39>qBhrAjqBh<17>iRKiRJgPL<10>REbPDdOEc<\
  17>0dG<16>pk0<8>bc8`b9ZaB<5>NVLLUNISPFQR<4>9IQ8GQ8FQ<4>BAMC9LF8K<12>n65<\
  22>LIH<26>zfz<19>DXz<6>M_k
  }
 
30079505           { ;
  reset=1920 type=julia passes=1
  corners=-0.067558046948356834/0.061097953051643158/-0.0509391106/0.04555\
  28894 params=0.4435773568133786/0.372177545877456 float=y
  maxiter=65536 inside=0
  colors=000N_i<15>ffAhg8ig6kh3kh4<39>qBhrAjqBh<17>iRKiRJgPL<10>REbPDdOEc<\
  17>0dG<16>pk0<8>bc8`b9ZaB<5>NVLLUNISPFQR<4>9IQ8GQ8FQ<4>BAMC9LF8K<12>n65<\
  22>LIH<26>zfz<19>DXz<6>M_k
  }
 
30079512           { ;
  reset=1920 type=julia passes=1
  corners=-0.29405321/-0.094053208/-0.94556367/-0.79556367
  params=0.4435772371283238/0.3721777480036303 float=y maxiter=65536
  inside=0
  colors=000N_i<15>ffAhg8ig6kh3kh4<39>qBhrAjqBh<17>iRKiRJgPL<10>REbPDdOEc<\
  17>0dG<16>pk0<8>bc8`b9ZaB<5>NVLLUNISPFQR<4>9IQ8GQ8FQ<4>BAMC9LF8K<12>n65<\
  22>LIH<26>zfz<19>DXz<6>M_k
  }
 
30079513           { ;
  reset=1920 type=julia
  corners=-0.000629970804/0.000881621614/-0.000599658117/0.000534337014
  params=-1.305531061568662/0.06280233095569003 maxiter=65536 inside=0
  colors=000zOn<25>zqPzsOzsP<29>zyxzzzyzz<45>FzgDzfDyf<37>KE9KC8KB7K96K85<\
  3>K21L00K00<8>900700600400300100000<9>P35S36V36Y36`37<6>r5At6Bw6Bz7Cz7C<\
  7>t5Cs5Cr5Cq4Cp4Co3B<6>h6Ig6Jh6K<6>k8Sl9Tm9Un9VnAW<19>yHqzIszJr<2>zNo
  }
 
30079514           { ;
  reset=1920 type=julia corners=-0.388/0.388/-0.291/0.291
  params=0.443577030416759/0.37217764578456 float=y maxiter=100000000
  inside=0
  colors=000SgG<10>WjFWjFXkEYkE<25>nqIoqJoqJoqJpqJ<4>roGroFroErnDsmC<17>sE\
  CrCCqCC<11>UCCSCDQCDOCEMCEKCFICFGCG<21>GCWFCXFCXECYECZ<8>ECgEChDChDDh<22\
  >DdrDfrDfr<35>CvtCvtCvs<45>NbINbINcI<12>SfG
  }