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Fractals/Iterations in the complex plane/Parameter plane
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Parameter plane
structure
algorithms
models
Structure of parameter plane
The phase space of a quadratic map is called its parameter plane. Here:
is constant
is variable
There is no dynamics here. It is only a set of parameter values. There are no orbits on the parameter plane.
The parameter plane consists of :
The Mandelbrot set
The bifurcation locus = boundary of Mandelbrot set
Bounded hyperbolic components of the Mandelbrot set = interior of Mandelbrot set Lasse Rempe, Dierk Schleicher : Bifurcation Loci of Exponential Maps and Quadratic Polynomials: Local Connectivity, Triviality of Fibers, and Density of Hyperbolicity
Structure of parameter plane from programmers point of view:
exterior of M-set
Each component is surrounded by an atom domain ( disc with radius 4 times bigger, for cardioids radius has about the square root of the size).
Each component has a nucleus at its center, which has a periodic orbit containing 0.
Parts of parameter plane
components ( incuding islands)
curves
points
curves or paths
The Mandelbrot set contains smooth curves:
the intersection with the real axis M ∩ R = [−2, 1/4] = real slice of Mandelbrot set
the main cardioid of M, which is the set of parameters c for which fc has an attracting or indifferent fixed point (of course, this is smooth except at the cusp c = 1/4).Generalizations of Douady's magic formula by Adam Epstein, Giulio Tiozzo
boundary of period 2 hyperbolic componenet, which is a circle
Paths:
external rays
internal rays
escape route
real slice
" each period-doubling cascade superstable orbit ... generate the corresponding chaotic band and the Misiurewicz point that separates the chaotic bands and "[Pastor97a] : Harmonic structure of one-dimensional quadratic maps by Gerardo Pastor, Miguel Romera, Fausto Montoya Vitini
where:
B is a chaotic region from -2 to MF
= Feigenbaum point = the Myrberg-Feigenbaum
A is a periodic region : from MF to 1/4
is the precedes symbol. The binary relationship: "x precedes y" is written: . It is used to distinguish other orders from total orders.
chaotic region
where:
is chaotic band
See also
separators between bands
It is a part of Sharkovsky ordering
periodic region
period doubling cascade
2^n = the powers of 2 in decreasing order, ending with 2^0 = 1." The On-Line Encyclopedia of Integer Sequences : A005408 = The odd numbers: a(n) = 2n+1
named parts of Mandelbrot set
Valley:
double spiral
spindle
seahorse valley/coast ( or Seahorse Valley East ) mandelmap - A detailed map of the Mandelbrot Set, in a beautiful vintage style by Bill Tavis
main cardioid seahorse valley = Gap between the head ( period 2 component) and the body (or shoulder = main cardioid). Particularly the upper one part.seahorsevalley From the Mandelbrot Set Glossary and Encyclopedia, by Robert Munafo, (c) 1987-2022
disk 3 seahorse valley = Gap between period 1 and period 3
Elephant Valley = Gap near cusp of main cardioid. Here the antennae resemble the trunks of elephantsmandelbrot-locations by woofractal
elephant coast = boundary of main cardioid near cusp
Scepter Valley = gap between period 2 and period 4 component, Also known as Seahorse Valley West or Sceptre Valley. "Scepter Valley" where double spirals have scepters coming (echoing the spindle) coming off of all their tips.Mandelbrot Buds and Branches by Timothy Chase Map of the Mandelbrot Set. Copyright © 2005-2011 Janet Parke
double spiral valley =
double spiral coast = boundary of period 2 component near main cardioid
triple spiral coast ( valley) - boundary of period 3 componnet near period 1 cardioid
Parts
Peacock eye = shrub ( decoration) from Seahorse valley = Principal Misiurewicz point with all branches
seahorse
elephant = limiting 1/n limb of main cardioid as n tends to infinity. See demo 2 page 10 from program mandel by Wolf Jung
Mini Mandelbrot sets
Names:
midget
mini mandelbrot set
baby Mandelbrots
island = island mu-molecule = island mu-unit the Mandelbrot Set Glossary and Encyclopedia, by Robert Munafo, (c) 1987-2018
primitive component
small copies of itself
babies Mandelbrot sets = BMSsM. Romera, G. Pastor, A. B. Orue, D. Arroyo, F. Montoya, "Coupling Patterns of External Arguments in the Multiple-Spiral Medallions of the Mandelbrot Set", Discrete Dynamics in Nature and Society, vol. 2009, Article ID 135637, 14 pages, 2009. https://doi.org/10.1155/2009/135637
Parameter rays of mini Mandelbrot sets Parameter rays of mini mandelbrot sets
" a saddle-node (parabolic) periodic point in a complex dynamical system often admits homoclinic points, and in the case that these homoclinic points are nondegenerate, this is accompanied by the existence of infinitely many baby Mandelbrot sets converging to the saddle-node parameter value in the corresponding parameter plane." Devaney Devaney In Global Analysis of Dynamical Systems, ed.: H. Broer, B. Krauskopf, G. Vegter. IOP Publishing (2001), 329-338 or Homoclinic Points in Complex Dynamical Systems
See also
How to find the angles of external rays that land on the root point of any Mandelbrot set's component which is not accessible from main cardioid ( M0) by a finite number of boundary crossing ?
distorted islands
Julia island or Embedded Julia Set or virtual Julia Sets or medallions
"A structure comprised of filaments, resembling a Julia set in appearance, which has a higher delta Hausdorff dimension than filaments in the immediately surrounding region. They are sometimes also called Julia islands or virtual Julia Sets." Robert Munafoembedded julia set from the Mandelbrot Set Glossary and Encyclopedia, by Robert Munafo, (c) 1987-2017.
"This location is called Julia island since it looks like a Julia set but it's actually inside Mandelbrot." https://www.flickr.com/photos/nonnameavailable/28654921940/
Medallions:
carrot = non-spiral medallion (-1.6898799090349986e-01 1.0423707254693195e+00 3.0218142193747843e-07 ) type: long double
cauliflower = single spiral medallion (-0.1543869 1.0308295 3.0218142193747843e-07 ) type: long double
double spiral medallion (-0.16092059 1.03663239 0.000001 ) type: long double
triple spiral medallion ( -1.5403777941777627e-01 1.0369221371305641e+00 6.5186720162412668e-07 ) type: long double
hyperbolic componenets
Components of the parameter plane
order of hyperbolic componenets
Myrberg 1963
Sharkovsky 1964
Metropolis 1973
internal adress by Lau and Schleicher 1994
rotation number by Devaney 1997
R2 naming system by R Munafo 1999https://www.mrob.com/pub/muency/r2namingsystem.html
orbit portrait by Milnor 2000
shrubs by M Romero et al 2004 M. Romera et al, Int. J. Bifurcation Chaos 13, 2279 (2003). https://doi.org/10.1142/S0218127403007941 Shrubs in the Mandelbrot Set Ordering
shape
ON THE SHAPES OF ELEMENTARY DOMAINS OR WHY MANDELBROT SET IS MADE FROM ALMOST IDEAL CIRCLES by V. Dolotin A.morozov
Algebraic Geometry of Discrete Dynamics. The case of one variable by V.Dolotin, A.Morozov
Parts of parameter plane
with respect to the Mandelbrot set
exterior
boundary with different point types: Cremer, Siegel, parabolic, Misiurewicz, Feigenbaoum, ...
interior
with respect to the wakes
inside a p/q wake
outside any wake (???)
Parts of Mandelbrot set according to M Romera et al.:SHRUBS IN THE MANDELBROT SET ORDERING by M Romero, G Pastor, G Alvarez, F Montoya
main cardioid
q/p family (= q/p limb)
periodic part: period doubling cascade of hyperbolic components which ends at the Myrberg-Feigenbaum point
the Myrberg-Feigenbaum point
chaotic part: shrub
Not that her q/p not p/q notation is used
Components of parameter plane:
wake / limb
migdet / island / mu-moleculemumolecule From the Mandelbrot Set Glossary and Encyclopedia, by Robert Munafo, (c) 1987-2020.
distortedfractalforums.com : how-distorted-can-a-minibrot-be = warpeddistribution From the Mandelbrot Set Glossary and Encyclopedia, by Robert Munafo, (c) 1987-2020
hyperbolic component of Mandelbrot set
Wake is a part of parameter plane between 2 parameter rays landing on the same parabolic point ( root point, bond)
Limb is a part of Mandelbrot set between 2 parameter rays landing on the same parabolic point ( root point, bond)
Strict ( math ) definition from the paper Periodic Orbits, Externals Rays and the Mandelbrot Set: An Expository Account by John W. Milnor
Theorem 1.2. The Wake . The two corresponding parameter rays land at a single point of the parameter plane. These rays, together with their landing point, cut the plane into two open subsets
and
with the following property: A quadratic map has a repelling orbit with portrait if and only if , and has a parabolic orbit with portrait if and only if .
Definitions:
the Mandelbrot set
This open set will be called the -wake in parameter space (compare Atela [A]),
will be called the root point of this wake
The intersectionIntersection_(set_theory) in wikipedia will be called the -limb of the Mandelbrot set
The open arc consisting of
all angles of dynamic rays which are contained in the interior of S1,
or all angles of parameter rays which are contained in , will be called the characteristic arc for the orbit portrait
Nomenclature types (source of the names):
mu-ency Mu-Ency - The Encyclopedia of the Mandelbrot Set by R Munafo
Mandelbrot papers and books
How to move on parameter plane ?
How to choose step of a move ?
fixed size step / adaptive size step
minimal size of the move
"For c values that could not be represented accurately by C++ double data type I calculated the images using interval arithmetics with tiny intervals (border values being fractions of 2^25, interval width 2^-25) encompassing the published value (as needed for real or imaginary part or both) (values were computed using wolfram-alpha to multiply large integers). Given is the left (smaller) border value, the right is obtained by adding one." marcm200fractalforums.org : julia-sets-true-shape-and-escape-time
What is the reason for : 2^-25 ?
"When I started with this article back in March this year, my initial formulas were z^2+c and z^2+c*z.
In expanded form with real coordinates: z=(x+i*y) and c=(d+e*i):
( x²-y² + d, 2xy + e ) or ( d*x + x² - e*y - y² , e*x + d*y + 2x*y )
To accurately represent a sum, the widest two terms can be apart is 53 bits (mantissa precision for C++ double) and all other must lie in this range.
The smallest non-zero value of x,y is "axis range / pixel count", i.e. 4 (escape radius of 2, hence axis -2..+2) divided by 2^refinement level.
So for x^2 this goes to 2^-26 as the lowest possible value for x. And since d,e are multiplied with x in the 2nd formula, the same goes for d and e. As I do not like to work "on the edge" I used a buffer of 1-2 bits and came to the lowest value of 2^-25 for d,e (and refinement level limit of 27 which is currently outside a reasonable range).
For the 1st formula z^2+c, the seed value could go as little as 2^-48 (stated in the article) as it is only added.
For long double and float128 one could go lower in both formulas, but I haven't explored that."marcm200fractalforums.org : julia-sets-true-shape-and-escape-time
Compare
Numerical calculations and rigorous mathematics
Reliable Computing, Interval Computations
Types
type of the move
continuous
discrete = using sequence of points
type of the curve
along radial curves :
escape route
external ray: From Cantor to parabolic Parameter along External RayFrom Cantor to Semi-hyperbolic Parameter along External Rays by Yi-Chiuan Chen and Tomoki Kawahira
parabolic point = root point = landing point of above external ray
internal ray: From Hyperbolic to Parabolic Parameters along Internal RaysFrom Hyperbolic to Parabolic Parameters along Internal Rays by Yi-Chiuan Chen and Tomoki Kawahira
along circular curves :
equipotentials
boundaries of hyperbolic components
internal circular curves
loops math.stackexchange question: parameter-plane-dynamics-of-fixed-points-and-their-preimages-for-standard-quadra
The dynamics of the polynomials of moving along curves is : Reading escaping trees from Hubbard trees in Sn by Matthieu Arfeux
for external ray: ”stretch” the dynamic on the basin of infinity. The argument of φPa,b (2a) stay unchanged ( fixed)
for equipotential: twist the dynamics in the annulus between the Green level curves of the escaping critical point and of the critical value. The modulus of φPa,b (2a is fixed
Examples
External ray
From Cantor to Semi-hyperbolic Parameters along External RaysFrom Cantor to Semi-hyperbolic Parameter along External Rays March 2018Transactions of the American Mathematical Society 372(11) DOI: 10.1090/tran/7839 Yi-Chiuan ChenTomoki KawahiraTomoki Kawahira
along parameter external ray for angle 9/31 by David Madore : Its external argument is constantly 9/31 and it approaches the bud's root (~ −0.481763 + +0.531657i) exponentially slowly.
external angle 1/3 by David Madore
Cantor to Misiurewicz: along the parameter ray of angle 15/56 by Tomoki Kawahira
Cantor to Parabolic along the parameter ray of angle 1/3: by Tomoki Kawahira
Boundary of the component
boundary of the largest bulb of the Mandelbrot set by David Madore
Others
morphing
poincare_half-plane_metric_for_zoom_animation by Claude Heiland-Allen
youtube: Julia sets as C pans over the Mandelbrot set by captzimmo
youtube : Julia sets about the main cardioid x 1.1 with Mandelbrot set by Thomas Fallon
youtube: Julia Sets Relative to the Mandelbrot Set by Gary Welz
you tube : Julia Sets of the Quadratic by Gary Welz
youtube : Julia set morph around the cardioid / central bulb by blimeyspod
youtube : Julia set morph / fractal animation - Beyond the Cardioid Perimiter by blimeyspod
youtube: Julia set morph / fractal animation - Beyond a 2nd Order Bulb by blimeyspod
Fractals: A tour of Julia Sets by corsec
shadertoy : Julia - Distance by iq
Evolving Julia Marco_Gilardi
// glsl code by iq from https://www.shadertoy.com/view/Mss3R8
float ltime = 0.5-0.5*cos(time*0.12);
vec2 c = vec2( -0.745, 0.186 ) - 0.045*zoom*(1.0-ltime);
// glsl code by xylifyx from https://www.shadertoy.com/view/XssXDr
vec2 c = vec2( 0.37+cos(iTime*1.23462673423)*0.04, sin(iTime*1.43472384234)*0.10+0.50);
// by Marco Gilardi
// https://www.shadertoy.com/view/MllGzB
vec2 c = vec2(-0.754, 0.05*(abs(cos(0.1*iTime))+0.8));
Escape route
Escape route 0
Escape route for internal angle 0/1
Steps
nucelus of period 1 component ( c = 0) Fixed point alfa is supperattracting fixed point. Julia set is connected.
along internal ray 0. Imaginary part of parameter c is zero. 0 < cx < 0.25. Fixed point alfa is attracting fixed point. Julia set is connected.
parabolic point c = 1/4. Fixed point alfa is parabolic fixed point. Julia set is connected.
along external ray 0. Imaginary part of parameter c is zero. 0.25 < cx. Fixed point alfa is repelling fixed point. Julia set is disconnected
Here parabolic implosion/ explosion ( from connected to disconnected ) occurs.
In parabolic point child periodic points coincides with parent period points
+ contious evolution of dynamics along escape route 0 ( parabolic implosion) parameter c location of c Julia set interior type of critical orbit dynamics critical point fixed points stability of alfa c = 0 center, interior connected exist superattracting atracted to alfa fixed point fixed critical point equal to alfa fixed point, alfa is superattracting, beta is repelling r = 0 0<c<1/4 internal ray 0, interior connected exist attracting atracted to alfa fixed point alfa is attracting, beta is repelling 0 < r < 1.0 c = 1/4 cusp, boundary connected exist parabolic atracted to alfa fixed point alfa fixed point equal to beta fixed point, both are parabolic r = 1 c>1/4 external ray 0, exterior disconnected disappears repelling repelling to infinity both finite fixed points are repelling r > 1
Stability r is absolute value of multiplier at fixed point alfa:
c = 0.0000000000000000+0.0000000000000000*I m(c) = 0.0000000000000000+0.0000000000000000*I r(m) = 0.0000000000000000 t(m) = 0.0000000000000000 period = 1
c = 0.0250000000000000+0.0000000000000000*I m(c) = 0.0513167019494862+0.0000000000000000*I r(m) = 0.0513167019494862 t(m) = 0.0000000000000000 period = 1
c = 0.0500000000000000+0.0000000000000000*I m(c) = 0.1055728090000841+0.0000000000000000*I r(m) = 0.1055728090000841 t(m) = 0.0000000000000000 period = 1
c = 0.0750000000000000+0.0000000000000000*I m(c) = 0.1633399734659244+0.0000000000000000*I r(m) = 0.1633399734659244 t(m) = 0.0000000000000000 period = 1
c = 0.1000000000000000+0.0000000000000000*I m(c) = 0.2254033307585166+0.0000000000000000*I r(m) = 0.2254033307585166 t(m) = 0.0000000000000000 period = 1
c = 0.1250000000000000+0.0000000000000000*I m(c) = 0.2928932188134524+0.0000000000000000*I r(m) = 0.2928932188134524 t(m) = 0.0000000000000000 period = 1
c = 0.1500000000000000+0.0000000000000000*I m(c) = 0.3675444679663241+0.0000000000000000*I r(m) = 0.3675444679663241 t(m) = 0.0000000000000000 period = 1
c = 0.1750000000000000+0.0000000000000000*I m(c) = 0.4522774424948338+0.0000000000000000*I r(m) = 0.4522774424948338 t(m) = 0.0000000000000000 period = 1
c = 0.2000000000000000+0.0000000000000000*I m(c) = 0.5527864045000419+0.0000000000000000*I r(m) = 0.5527864045000419 t(m) = 0.0000000000000000 period = 1
c = 0.2250000000000000+0.0000000000000000*I m(c) = 0.6837722339831620+0.0000000000000000*I r(m) = 0.6837722339831620 t(m) = 0.0000000000000000 period = 1
c = 0.2500000000000000+0.0000000000000000*I m(c) = 0.9999999894632878+0.0000000000000000*I r(m) = 0.9999999894632878 t(m) = 0.0000000000000000 period = 1
c = 0.2750000000000000+0.0000000000000000*I m(c) = 1.0000000000000000+0.3162277660168377*I r(m) = 1.0488088481701514 t(m) = 0.0487455572605341 period = 1
c = 0.3000000000000000+0.0000000000000000*I m(c) = 1.0000000000000000+0.4472135954999579*I r(m) = 1.0954451150103321 t(m) = 0.0669301182003075 period = 1
c = 0.3250000000000000+0.0000000000000000*I m(c) = 1.0000000000000000+0.5477225575051662*I r(m) = 1.1401754250991381 t(m) = 0.0797514300099943 period = 1
c = 0.3500000000000000+0.0000000000000000*I m(c) = 1.0000000000000000+0.6324555320336760*I r(m) = 1.1832159566199232 t(m) = 0.0897542589928440 period = 1
+ Real slice of parameter plane: imag(c) = 0 parameter c value description of c locations fixed points Julia set basins target set ( petal) 1/4 < c point c is on the external ray 0 both fixed points are repelling disconnected only ona basin of attraction ( infinity) c = 1/4 cusp of main carioid both fixed points are parabolic ( belong to Julia set) connected = Cauliflower circle 0 < c < 1/4 inside main cardioid, along internal ray 0 Treść komórki Treść komórki c = 0 center of main cardioid Treść komórki Treść komórki 0 < c < 3/4 inside main cardioid, along internal ray 1/2 Treść komórki Treść komórki c = 3/4 root point ( parabolic) Treść komórki Treść komórki 3/4 < c < 1.0 inside period 2 component, along internal ray 0 Treść komórki Treść komórki c = 1.0 center of period 2 component Treść komórki Treść komórki 1/0 < c < 5/4 inside period 2 component, along internal ray 1/2 Treść komórki Treść komórki c = 5/4 root point ( parabolic) Treść komórki Treść komórki
stability index of period 1 points period 1 points on dynamic plane period 1 points on parameter plane changes from attractive through indifferent to repelling moves from interior of Kc to its boundary moves from interior of componetnt of M-set to its boundary
Escape route 1/3
Plane types
Criteria for plane classifications
fractal formula ( function): c-plane, lambda-plane
plane transformations
There are many different types of the parameter planeAlternate Parameter Planes by David E. Joyce
exponentialmap by Robert Munafo
by function
plain c-plane:
plain lambda plane where
by transformations Twisted Mandelbrot Sets by Eric C. HillOn quasi-conformal (in-) compatibility of satellite copies of the Mandelbrot set: I by Luna Lomonaco, Carsten Lunde Petersen
inverted c-plane = 1/c plane:
exponential plane ( map) mu-ency : exponential map by R MunafoExponential mapping and OpenMP by Claude Heiland-Allenexponential_mapping_with_kalles_fraktaler by Claude Heiland-Allen
unrolled plain (flatten' the cardiod = unroll ) Linas Vepstas : Self Similar?the flattened cardioid of a Mandelbrot by Tom Rathborne = "A region along the cardioid is continuously blown up and stretched out, so that the respective segment of the cardioid becomes a line segment. .." ( Figure 4.22 on pages 204-205 of The Science Of Fractal Images)Stretching cusps by Claude Heiland-Allen
See also
Mandelbrot Sets: Alternate Parameter Planes
Parameter space types by dimensions
1D ( 1 real parameter):
2D ( 1 complex parameter): standard Mandelbrot set, here space is a 2D plane
4D ( 2 complex parameters) : the family f(z) = z^n+A*z+c by marcm200
6D ( 3 complex parameters) : six dimensional space of the complex parameters m, b, and d used in the formula f(x)=mx(1-x)(x+b)/(x+d) by Valannorton
One can only show 2D slice in the multi dimensional space.
Points
realTotally real points in the Mandelbrot Set by Xavier Buff, Sarah Koch 2022
How to describe c point ?
Numerical description
c value
Cartesion description
real part
imaginary part
polar description:
(external or internal ) angle
( external or internal) radius, see stability index
Symbolic description
set relation: Julia set interior / boundary / exterior
How to save parameters of the point?
parameter files: files with saved parameter values
image files with saved parameters
examples of important points
Examples from the parameter plane and Mandelbrot set:
The northwest external angle is 3/8
The north external angle is 1/4North by Robert P. Munafo, 2010 Sep 20. From the Mandelbrot Set Glossary and Encyclopedia, by Robert Munafo, (c) 1987-2022.
The northeast external angle is 1/8Northeast by Robert P. Munafo, 2010 Sep 20. From the Mandelbrot Set Glossary and Encyclopedia, by Robert Munafo, (c) 1987-2022.
The west external angle is 1/2
The east external angle is 0
The southwest external angle is 5/8
The south external angle is 3/4
The southeast external angle is 7/8,
Point Types
point
pixel of parameter plane
c parameter of complex quadratic polynomial
complex number
point coordinate
Criteria
Criteria for classification of parameter plane points :
arithmetic properties of internal angle (rotational number) or external angle
in case of exterior point:
type of angle : rational, irrational, ....
preperiod and period of angle under doubling map
in case of boundary point :
preperiod and period of external angle under doubling map
preperiod and period of internal angle under doubling map
set properties ( relation with the Mandelbrot set and wakes)
interior
boundary
exterior
inside wake, subwake
outside all the wakes, belonging to a parameter ray landing at a Siegel or Cremer parameter,
geometric properties
number of external rays that land on the boundary point : tips ( 1 ray), biaccessible, triaccessible, ....
position of critical point with relation to the Julia set
Renormalization
Classification
There is no complete classification. The "unclassifed" parameters
are uncountably infinite, as are the associated angles.
Simple classification
exterior of Mandelbrot set
Mandelbrot set
boundary of Mandelbrot set
interior of Mandelbrot set ( hyperbolic parameter)
centers,
other internal points ( points of internal rays )
Definitions
a parameter c in the boundary of Mandelbrot set ∂M is semi-hyperbolic if the critical point is non-recurrent and belongs to the Julia setFrom Cantor to Semi-hyperbolic Parameter along External Rays March 2018Transactions of the American Mathematical Society 372(11) DOI: 10.1090/tran/7839
A typical example of semi-hyperbolic parameter is a Misiurewicz point: We say a parameter ˆc is Misiurewicz if the critical point of fcˆ is a pre-periodic point.
partial classification of boundary points
Classification :stackexchange : classification-of-points-in-the-mandelbrot-set
Boundaries of primitive and satellite hyperbolic components:
Parabolic (including 1/4 and primitive roots which are landing points for 2 parameter rays with rational external angles = biaccessible ).
Siegel ( a unique parameter ray landing with irrational external angle)
Cremer ( a unique parameter ray landing with irrational external angle)
Boundary of M without boundaries of hyperbolic components:
non-renormalizable (Misiurewicz with rational external angle and other).
renormalizable
finitely renormalizable (Misiurewicz and other).
infinitely renormalizble (Feigenbaum and other). Angle in turns of external rays landing on the Feigenbaum point are irrational numbers
non hyperbolic components ( we believe they do not exist but we cannot prove it ) Boundaries of non-hyperbolic components would be infinitely renormalizable as well.
Here "other" has not a complete description. The polynomial may have
a locally connected Julia set or not, the critical point may be rcurrent
or not, the number of branches at branch points may be bounded
or not ...
How to choose a point from parameter plane ?
take point ( and check it's properities)
taking parameter choosing by other people (visual choose)
clicking on parameter points and see what you have ( random choose)fractalforums : parameter-adjustment-art-or-luck ?
computing a point from it's known properties
For (parabolic point ) choose hyperbolic component ( period, number) and internal angle (= rotation number) then compute c parameter.
Misiurewicz points interesting c points by Owen Maresh
see also known regins in Visual Guide To Patterns In The Mandelbrot Set by Miqel
morphing
interesting areasfractalforums : deep-zooming-to-interesting-areas
zoom
autozoom
math.stackexchange question: value-to-use-as-center-of-mandelbrot-set-zoom
Mandelbrot Examples with parameters by David J. Eck
examples
Is parameter tweaking an acquired art or just random chance?
"From my own experience with monocritical polynomials and Lyapunov diagrams, all my images I found purely by chance.
For z^2+c e.g. as long as you're in the same hyperbolic component, the shape changes only in the sense, that a fat spiral might become thinner, but the number of arms stays constant.
If you move the c value out of that component into another - and if this 2nd component is not directly attached to the first, then, I'm not aware of a direct way of telling what it would look like there.
Usually I perform a parameter walk just computing black and white escape images with periodicity. Then for the interesting shapes/periods I apply a color walk with some gradients that looked fine in previous images.
But that's more or less guessing.
If you want to turn more into the constructing-an-image from a vision you have, you might try two articles: genetic algorithm and Leja points" marcm200fractalforums.org : parameter-adjustment-art-or-luck
Mandelbrot set : z^6+ A*z+c How do you find such intereseting examples ?
" I'm running from time to time an A,c-parameter space walk (brute force) in a rather wide grid (-2..+2 in ~0,01 or larger steps) for the family z^n+A*z+c, adding a small random dyadic fraction to the 4d coordinates to get variation.
Following numerically the orbits of the critical points with a rather high max it of 25000 it's possible to get the number of attracting cycles and their length to some accuaracy level in a decent time. If those A,c-parameter pairs pass some filters (mostly sum of length of cycles and diversity) I scan through small overview pictures manually.
Then I use interesting A,c pairs (shape-wise or from the filter values) and some small deviations from it to compute level 10-12 TSA images, as sets wiith similar shapes can show a different dynamical behaviour w.r.t. the level at which interior cells emerge.
I'll take the fastest one and see how many cycles can be detected up to level 18-19." marcm200fractalforums.org: julia-sets-true-shape-and-escape-time
Curves
Curves on the parameter plane
rays
Parameter External Ray
internal rays
equipotential curves
boundary
of whole Mandelbrot set
of hyperbolic components
Algorithms
general or representation functions
Boolean_escape_time
BDM/M
Complex potential
atom domains
bof60
The_Lyapunov_exponent
True shape
Discrete Langrangian Descriptors
combinatorial : tuning
wake
principle Misiurewicz points for the wake k/r of main cardioid
subwake, tuning and internal address
roots, islands and Douady tuning
Julia morphing - to sculpt shapes of Mandelbrot set parts ( zoom ) and Show Inflection
Models
Structure of the Mandelbrot set
Sharkovsky ordering
Size or area
mandelbrot-area by Kerry Mitchell ( 2001)
The size of Mandelbrot bulbs by A.C. Fowler Mark J. Mcguinness
How to to determine the ideal number of maximum iterations for an arbitrary zoom level in a Mandelbrot fractal
a-way-to-determine-the-ideal-number-of-maximum-iterations-for-an-arbitrary-zoom
Automatic Dwell Limit From the Mandelbrot Set Glossary and Encyclopedia, by Robert Munafo, (c) 1987-2023.
stackoverflow question: how-many-iterations-of-the-mandelbrot-set-for-an-accurate-picture-at-a-certain-z
stackoverflow question: calculate-a-dynamic-iteration-value-when-zooming-into-a-mandelbrot
Adaptive maxiter depending on the inverse square root of the magnification
See also
Types of Julia sets
Exact Coordinates by Robert P. Munafo, 2003 Sep 22.
Rational Coordinates by Robert P. Munafo, 2012 Apr 22.
Rerferences