class pt {double x,y,z}

flow distance(double dx,dy,dz) into double distance
    {
    distance = sqrt(dx*dx + dy*dy + dz*dz);
    }

flow normalize(array of pt a) into array of pt normalized
    {
    normalized = ();
    for (i in 0 til a.size)
        {
	pt p = a[i];
	double len = distance(p.x,p.y,p.z);
	pt norm;
	if (len > 0)
	    {
	    double scale = 1/len;
	    norm = (p.x*scale, p.y*scale, p.z*scale);
	    }
	else
	    norm = (0,0,0);
	normalized.append(norm);
	}
    }

to makeRandomArrayOfPt(int size) into array of pt array
    {
    array[size] of pt a;
    for (i in 0 til size)
        {
	double scale = random()*10;
	a[i] = (scale*random(), scale*random(), scale*random());
	}
    array = a;
    }

to makeRandomArrayArray(int size) into array of array of pt aa
    {
    aa = ();
    for (i in 0 til size)
	aa.append(makeRandomArrayOfPt(random()*1000));
    }


array of array of pt aa = makeRandomArrayArray(100);
for (i in 0 til 10)
   {
   para(a in aa) do
   // for (a in aa)
       {
       array of pt norm = normalize(a);
       }
    }
    
print("Looks ok");