final SobolRsg rsg = new SobolRsg(5, seed);
final double tolerance = 1.7e-4;
// actually tested up to 2^21-1=2097151 Sobol draws
for (int i = 0; i < 1023; ++i) {
final double next[] = rsg.nextSequence().value();
// TODO: translate properly
// s = grid[0].front() + next[0]*(grid[0].back()-grid[0].front());
// t = grid[1].front() + next[1]*(grid[1].back()-grid[1].front());
// u = grid[2].front() + next[2]*(grid[2].back()-grid[2].front());
// v = grid[3].front() + next[3]*(grid[3].back()-grid[3].front());