public static float turbulence2(float x,float y,float octaves){
  float t=0.0f;
  for (float f=1.0f; f <= octaves; f*=2)   t+=Math.abs(noise2(f * x,f * y)) / f;
  return t;
}

public static float turbulence2 ( float x , float y , float octaves ) { float t = 0.0f ; for ( float f = 1.0f ; f <= octaves ; f *= 2 ) t += Math . abs ( noise2 ( f * x , f * y ) ) / f ; return t ; }
compute turbulence using perlin noise .
