Hi, I'm new here, downloaded processing yesterday and registered today. To cut to the chase, had a quick look at some of the examples (presumably aimed at beginners) and some have a bit of a hackish appearance. Having already done a bit of straight java (swing etc) and recently been getting into the nuts and bolts of C++ I appreciate the straight forward accessibility of what I see here. Any how, not done much yet, but I think I might have imperoved the radial colour example a tad - It seems to prefer jumping from cartesian to polar rather than just stay in polar avoiding an unnecesary radians() conversion. Like thus:
Code:

/**
 * Simple Radial Gradient 
 * by Ira Greenberg. 
 * 
 * Using the convenient red(), green() 
 * and blue() component functions,
 * generate an array of radial gradients.
 */
 
void setup(){
  size(600, 600);
  background(0);
  smooth();

  // create a simple table of gradients
  int columns = 4;
  int radius = (width/columns)/2;
  // create some gradients
  for (int i=radius; i< width; i+=radius*2){
    for (int j =radius; j< height; j+=radius*2){
	createGradient(i, j, radius, 
	color(int(random(255)), int(random(255)), int(random(255))), 
	color(int(random(255)), int(random(255)), int(random(255))));
    }
  }
}

void createGradient (float x, float y, float radius, color c1, color c2){
  float px = 0, py = 0, angle = 0;

  // calculate differences between color components 
  float deltaR = red(c2)-red(c1);
  float deltaG = green(c2)-green(c1);
  float deltaB = blue(c2)-blue(c1);
  // hack to ensure there are no holes in gradient
  // needs to be increased, as radius increases
  float gapFiller = 12.0;
  float increment=(TWO_PI)/(360*gapFiller);// adds clarity being next to   gapfiller def
  for (int i=0; i< radius; i++){
    for (float j=0; j<TWO_PI; j+=increment){
	px = x+cos(angle)*i;
	py = y+sin(angle)*i;
	angle+=increment;
	color c = color(
	(red(c1)+(i)*(deltaR/radius)),
	(green(c1)+(i)*(deltaG/radius)),
	(blue(c1)+(i)*(deltaB/radius)) 
	  );
	set(int(px), int(py), c);	
    }
  }
  // adds smooth edge 
  // hack anti-aliasing
  noFill();
  strokeWeight(3);
  ellipse(x, y, radius*2, radius*2);
}
 

Only a suggestion
Many thanks for a brilliant API and IDE

Man on a mission