Another possible way to accelerate MB set deep zooming

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Offline knighty

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« Reply #165 on: August 04, 2018, 06:03:40 PM »
Cool!
Could you provide a Windows executable if such thing is possible? I don't have Haskell...
Those kind of glitches are probably caused by inaccurate escape radius estimation. Try using higher "orderM" or reduce the escape radius by some factor. For now the escape radius estimate is not very good. It needs some research. There are two questions to answer in order to get a better escape radius:
- how close is the bi-polynomial to a quadratic function ? There is a region around z=0 where the bi-polynomial is quadratic-like. How big is that region?
- how good is the bi-polynomial at approximating f(on)(z,c) ? Or how big is the region where the approximation error smaller than a tolerance?
Another question is about the dependency of the escape radius on the c parameter...

Maybe an adaptive maxiters could be a neat trick, base it on the period of the first minibrot (ordered from deep to shallow) whose superbailout we are within ?  Don't know what the best scaling formula would be.  Did you share your latest code?

EDIT: simpler just to use si < 1000 = maxsi and set maxiters = period * maxsi, seems to work in one test
That's a good method IMHO.

The code I'm working on have become a real mess. I don't think is would be helpful. Moreover, the comments may be misleading. I haven't found a good way to solve the glitches issue. I'm pretty sure it is solvable using the "super PT". The question is how to determine the good approximating (bi-)polynomials sequence ?

Anyway, here it is.

Offline claude

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« Reply #166 on: August 06, 2018, 12:03:39 AM »
No windows executable(s), the code is structures as many independent programs orchestrated by a bash script.  Sorry.  Maybe that WSL or whatever it is will be more productive, it's all CLI stuff so should work fine.  Or try a traditional VM.

Offline gerrit

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« Reply #167 on: August 06, 2018, 03:19:01 AM »
PT glitch correction when based on non-escaping reference point (nuclei) usually requires higher period mini's than the first reference.
It's not the same, but maybe something similar prevents SSA2 (1=SSA + PT, 2 = SSA all the way) from working.

Offline gerrit

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« Reply #168 on: August 15, 2018, 05:23:42 AM »
Would it be possible to make some small adjustments to the last nanomb binary:
https://fractalforums.org/fractal-mathematics-and-new-theories/28/another-possible-way-to-accelerate-mb-set-deep-zooming/277/msg8132#msg8132

It works very well, but there is a problem with "long double" which is much slower than "floatexp".

The other problem is the kfb export which is not completely compatible with KF. My workflow is render with nanamb then postprocess KFB in KF. When imported in KF you get all sorts of weird colors in the mini (interior DE).
I wrote a script to replace all negative entries in the KFB file with 0, but when importing to KF it still does not recognize interior points as interior points, but gives them some color. Workaround for me is to the replace that color with black in photoshop which works unless I'm unlucky and that color appears elsewhere.

An option not so save (negative) interior DE data would be good.

With those changes I think this is a great external rendering tool.

Offline claude

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« Reply #169 on: August 15, 2018, 10:29:21 PM »
I wrote a script to replace all negative entries in the KFB file with 0, but when importing to KF it still does not recognize interior points as interior points, but gives them some color.
I think you should replace negative DE like this:
the integer iteration count -> the maxiters value found in the KFB header (this signals the colouring to consider it as interior)
the floating point fraction iteration count -> 0 (anything other than -1 might work, -1 signals that it is a glitch)
the distance estimate (negative) -> absolute value of distance estimate (anything might work, it's not used for interior)

Offline gerrit

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« Reply #170 on: August 16, 2018, 12:36:07 AM »
Thanks. Just setting the integer count to maxiter suffices it seems.


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