float x, y;

void setup() {
  size(400, 400);
  background(0);
  stroke(255);
  x = width / 2;
  y = height / 2;
}

void draw() {
  point(x, y);
  x += random(-3, 3);
  y += random(-3, 3);
  //println("x= "+nf(x,0,2)+" and y= "+nf(y,0,2));
  //uncomment the previous line to see x and y values on the console
}
//test