// G-Force DeltaField
// Name: HAL_Standard_Map
// Created by: Howard A. Landman, 8-9 July 2001
// e-mail: howard@polyamory.org
// homepage: http://www.polyamory.org/~howard/

// Another classical chaotic attractor, called the "standard map".
// See e.g. Rasband, "Chaotic Dynamics of Nonlinear Systems", section 8.5
// As usual, recursion is run backwards and has been scaled to fit
// the screen better.  Probably here the X could be stretched more than
// the Y, but I didn't do that so as to preserve the aspect ratio of the
// original attractor.

Aspc=0,

A0="2",		// scale factor, larger A0 => bigger fractal
A1="2*PI/a0",	// precompute

srcX="x - sin(a1*y)/a1",
srcY="y + x - sin(a1*y)/a1",

Vers=200