So,
what happened to it? What's the end of the story?

Simen.

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Simen Kvaal <sim### [at] studentmatnatuiono> wrote:
: So,
: what happened to it? What's the end of the story?

  I have sent the current version to Nathan and Ron, so it should appear
with the next versions of uvpov and superpatch.
  Currently I'm just collecting improvement ideas. When I get enough precise
suggestions, I will probably add them to the patch and send a new version.
Don't expect this to happen in a very near future.
  The current patch should be powerful enough for anyone interested to
explore hours and hours its possibilities, though.

  I'm very glad that someone cares. Thank you.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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On 17 Nov 1999 05:57:46 -0500, Nieminen Juha
<war### [at] punarastascstutfi> wrote:

>Simen Kvaal <sim### [at] studentmatnatuiono> wrote:
>: So,
>: what happened to it? What's the end of the story?
>
>  I have sent the current version to Nathan and Ron, so it should appear
>with the next versions of uvpov and superpatch.
>  Currently I'm just collecting improvement ideas. When I get enough precise
>suggestions, I will probably add them to the patch and send a new version.
>Don't expect this to happen in a very near future.
>  The current patch should be powerful enough for anyone interested to
>explore hours and hours its possibilities, though.
>
>  I'm very glad that someone cares. Thank you.

Did you eventually code Mark's mandel3d fractal? How about the various
z functions (sin, cos etc.)?

BTW I spent three days searching for info on how to raise a complex
number to a complex power. I found no explanation, anywhere, though I
did find some commercial C and Python libraries for doing it. For now,
I'll just consider it impossible.

The filters in Fractal Explorer that I mentioned were written as some
weird formulas using notation I had not seen anywhere else. So much on
those...

The Julibrot is a really beautiful, but quite slow fractal. Maybe you
could consider adding it, too. There's a detailed explanation in the
FractInt help.

And the last suggestion -- how about .FRM parsing? That will be the
hardest one to write, maybe some of the code is already in the
Isosurface formula parser. Maybe not. Think about it...

See? Someone else cares :)


Peter Popov
ICQ: 15002700

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Peter Popov <pet### [at] usanet> wrote:
: Did you eventually code Mark's mandel3d fractal?

  Not yet. I'm a perfectionist and I would like a precise formula
(like z(n+1) = z(n)^2+c) instead of a trial-and-error-trying-type waving
of hands formula.

: How about the various z functions (sin, cos etc.)?

  Like the julia_fractal uses? Perfectly possible. I just have to think about
a way of doing it that minimizes typing work.
  It might not be impossible even to use a user-defined isosurface function.
However, I will probably wait for pov3.5 for that.

: The Julibrot is a really beautiful, but quite slow fractal. Maybe you
: could consider adding it, too. There's a detailed explanation in the
: FractInt help.

  Isn't the Julibrot just the julia_fractal already as an object in povray?
That is, the regular julia set but using hypercomplex or quaternion numbers
instead of complex numbers.
  It shouldn't be hard to make some modifications so that the current
julia_fractal could also be used as a pattern. I have to look at it.

: See? Someone else cares :)

  Thanks :)

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Peter Popov <pet### [at] usanet> writes:

> On 17 Nov 1999 05:57:46 -0500, Nieminen Juha
> 
> BTW I spent three days searching for info on how to raise a complex
> number to a complex power. I found no explanation, anywhere, though I
> did find some commercial C and Python libraries for doing it. For now,
> I'll just consider it impossible.

This is not too diffucult. You probably know the equations for real numbers:
a^c = exp(log(a^c)) = exp(c*log(a))
We use this to define a it for complex numbers:
(a+ib)^(c+id) := exp( (c+id)*log(a+ib))
Of course, you must also know how to calculate the definition of the complex 
exponentional function:
exp(a+ib) = exp(a) * exp(ib) = exp(a) * ( cos b + i sin b )
The problem is the definition of the complex logarithm. It is not possible
to define it as a continuous function. You can however define it for all 
complex numbers except real ones that are lower or equal zero. As formula:
C \ { a+ib | a,b in R, a<=0 and b=0 }
Every such number can be described as r*exp(i*p) with 
  r in ]0;infinity[ being sqrt(a*a+b*b)
  p in ]-pi,pi[     being the angle (1,0) (0,0) (a,b)
Now, the (or more precisely a) complex logarithm can be defined as:
  log(r) + i*p

Play around with these formulas to find an efficient way to calculate the
complex power function.

I hope this helps.

Thomas

P.S.: I'm sure that there're others who know much more about this subject
than I do.

-- 
http://thomas.willhalm.de/
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