28
Fractals Self Similarity and Fractal Geometry presented by Pauline Jepp 601.73 Biological Computing

Fractals - University of Calgary in Alberta · 2002. 4. 17. · Fractals Self Similarity and Fractal Geometry presented by Pauline Jepp 601.73 Biological Computing. Overview History

  • Upload
    others

  • View
    3

  • Download
    0

Embed Size (px)

Citation preview

  • Fractals

    Self Similarity and Fractal Geometry

    presented by Pauline Jepp601.73

    Biological Computing

  • Overview

    History

    Initial Monsters

    Details

    Fractals in Nature

    Brownian Motion

    L-systems

    Fractals defined by linear algebra operators

    Non-linear fractals

  • History

    Euclid's 5 postulates:

    1. To draw a straight line from any point to any other.

    2. To produce a finite straight line continuously in a straight line.

    3. To describe a circle with any centre and distance.

    4. That all right angles are equal to each other.

    5. That, if a straight line falling on two straight lines make the interior angles on the sameside less than two right angles, if produced indefinitely, meet on that side on which arethe angles less than the two right angles.

  • History

    Euclid ~ "formless" patterns

    Mandlebrot's Fractals

    "Pathological" "gallery of monsters"

    In 1875:

    Continuous non-differentiablefunctions, ie no tangent La Femme Au Miroir 1920

    Leger, Fernand

  • Initial Monsters

    1878 Cantor's set

    1890 Peano'sspace filling curves

  • Initial Monsters

    1906 Koch curve

    1960 Sierpinski'striangle

  • Details

    Fractals :

    are self similar

    fractal dimension

    A square may be broken into N^2 self-similar pieces,each with magnification factor N

  • Details

    Effective dimensionMandlebrot: " ... a notion that should not be defined precisely. It is an intuitiveand potent throwback to the Pythagoreans' archaic Greek geometry"

    How long is the coast of Britain?Steinhaus 1954, Richardson 1961

  • Brownian Motion

    Robert Brown 1827

    Jean Perrin 1906

    Diffusion-limited aggregation

  • L-Systems and Fractal Growth

    Packing efficiency

    Axiom &production rulesAxiom: BRules: B->F[-B]+B

    F->FFB

    F[-B]+B

    FF[-F[-B]+B]+F[-B]+B

  • L-Systems and Fractal Growth

    Turtle graphicsSeymour Papert

  • L-Systems and Fractal Growth

  • L-Systems and Fractal Growth

  • L-Systems and Fractal Growth

  • Affine Transformation Fractals

    "It has a miniature version of itself embedded inside it, but the smaller versionis slightly rotated."

    Transofrmations:

    translation,

    scale,

    reflection

    rotation

  • Affine Transformation Fractals

    Michael Barnsley

    Multiple Reduction Copy Machine Algorithm(MRCM)

  • Affine Transformation Fractals

    Multiple Reduction Copy Machine Algorithm(MRCM)

  • Affine Transformation Fractals

    Iterated Functional Systems (IFS)

  • Affine Transformation Fractals

    Iterated Functional Systems (IFS)

  • Affine Transformation Fractals

    Iterated Functional Systems (IFS)

  • Affine Transformation Fractals

    Iterated Functional Systems (IFS)

  • The Mandelbrot & Julia sets

    Iterative Dynamical Systems

  • The Mandelbrot & Julia sets

    For each number, c, in a subset of the complex plane

    Set x0 = 0

    For t = 1 to tmax

    Compute xt = x2t + c

    If t< tmax, then colour point c white

    If t = tmax, then colour point c black

  • The Mandelbrot & Julia sets

  • The Mandelbrot & Julia sets

    M-Set and computability

    cardoid:x = 1/4(2 cos t - cos 2t )y = 1/4(2 sint t - sin 2 t )

  • The Mandelbrot & Julia sets

    The M-Set as the Master Julia set.Set c to some constant complex value

    For each number, x0 in a subset of the complex plane

    For t = 1 to tmax

    Compute xt = xt2 + c

    If |xt| > 2 then break out of loop

    If t < tmax then colour point c white

    It t = tmax thencolour point c black

  • The Mandelbrot & Julia sets

  • The Mandelbrot & Julia sets