• December 11, 2017, 04:05:48 PM

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Author Topic:  Several Problems / Errors  (Read 60 times)

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Offline PMH

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Several Problems / Errors
« on: December 04, 2017, 08:02:15 PM »
* When I zoom out the -x-axis, eventually, KF displays the same RE coordinate regardless (1.99987353023144981554402187326482504512)

* Do I really have to switch back & forth between Animate Zoom and not in order to zoom and drag? (ieg, no special key modifier?)

* Do I really have to tell it what kind of reals to use for its computation?  How about <accurate enough for what I ask it to do?>  similaerly for (any) max-iterations.

* Why does Show Iterations reset?

Offline claude

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Re: Several Problems / Errors
« Reply #1 on: December 05, 2017, 09:16:29 PM »
Which version are you using?
* When I zoom out the -x-axis, eventually, KF displays the same RE coordinate regardless (1.99987353023144981554402187326482504512)
It may be a bug, but why do you want to zoom like that?  In any case I can't reproduce this in 2.12.6.
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* Do I really have to switch back & forth between Animate Zoom and not in order to zoom and drag? (ieg, no special key modifier?)
Ctrl-left-click zooms in with a box you can position before mouseup, right-click zooms out, unmodified left click drags the image.  Mouse wheel zooms too.
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* Do I really have to tell it what kind of reals to use for its computation?  How about <accurate enough for what I ask it to do?>  similaerly for (any) max-iterations.
Number type is automatic, you can override if it isn't good enough.  If you have locations where overriding matters then please attach the parameters so I can test.
Automagic max-iterations is tricky with the architecture of KF, which calculates the whole reference orbits in advance of the per-pixel iterations.  It would require a major rewrite to implement.
I have a different renderer (mandelbrot-pertubator, but no easy way for you to run it, sorry) I work on too, this one interleaves the computations so you can have say 10M or 100M maxiterations and it will not necessarily take forever if all the pixels escape.  I think I would rather spend my time porting formulas and making an installer for mandelbrot-perturbator than rewriting KF in that way.
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* Why does Show Iterations reset?
It's a one-shot effect, not a permanent setting.  Don't know why it is implemented like that, I only took over KF maintenance this year.

Offline PMH

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Re: Several Problems / Errors
« Reply #2 on: December 05, 2017, 10:05:50 PM »
great answer!

I like zooming out the -X axis to look for the largest m nearest -2.
(I bet there's a better way.)

May I just add that it looks like KF's escape radius is <2.  I must be wrong, but that's what the equi-iteration curves look like.  I haven't seen that since the first M-zoom applications (ours).

Offline PMH

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Re: Several Problems / Errors
« Reply #3 on: December 05, 2017, 10:09:24 PM »
version 2.12.6 (I installed it only a few days ago)

Offline claude

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Re: Several Problems / Errors
« Reply #4 on: December 07, 2017, 03:08:59 PM »
I like zooming out the -X axis to look for the largest m nearest -2.
(I bet there's a better way.)
I think that's normally called zooming in, not out.  But it works fine here.  As for a better way, maybe enter a location manually like -2 0 1e100 and use Newton-Raphson zooming (special menu, Ctrl-D) - if you get a fully black screen then increase the maximum iterations...

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May I just add that it looks like KF's escape radius is <2.  I must be wrong, but that's what the equi-iteration curves look like.  I haven't seen that since the first M-zoom applications (ours).
default escape radius is 10000, but 2 is an option (set iterations dialog smooth method to "bailout=2" instead of "high bailout").

Offline PMH

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Re: Several Problems / Errors
« Reply #5 on: December 07, 2017, 04:43:37 PM »
I meant "zooming in - out the -X-axis towards -2".

Re escape radius:  Sorry; that's about a different Mandelbrot generator!