### 60.2 Definitions for IFS fractals

Some fractals can be generated by iterative applications of contractive affine transformations in a random way; see

Hoggar S. G., "Mathematics for computer graphics", Cambridge University Press 1994.

We define a list with several contractive affine transformations, and we randomly select the transformation in a recursive way. The probability of the choice of a transformation must be related with the contraction ratio.

You can change the transformations and find another fractal

Function: sierpinskiale (n)

  Sierpinski Triangle: 3 contractive maps; .5 contraction constant and translations; all maps have the same contraction ratio. Argument n must be great enough, 10000 or greater.

  Example:

      (%i1) load("fractals")$
      (%i2) n: 10000$
      (%i3) plot2d([discrete,sierpinskiale(n)], [style,dots])$

  ·

  Categories: Package fractals

Function: treefale (n)

  3 contractive maps all with the same contraction ratio. Argument n must be great enough, 10000 or greater.

  Example:

      (%i1) load("fractals")$
      (%i2) n: 10000$
      (%i3) plot2d([discrete,treefale(n)], [style,dots])$

  ·

  Categories: Package fractals

Function: fernfale (n)

  4 contractive maps, the probability to choice a transformation must be related with the contraction ratio. Argument n must be great enough, 10000 or greater.

  Example:

      (%i1) load("fractals")$
      (%i2) n: 10000$
      (%i3) plot2d([discrete,fernfale(n)], [style,dots])$

  ·

  Categories: Package fractals