double theta = Math.Atan2(curly[i, j, k], curlx[i, j, k]);
double phi = Math.Acos(curlz[i, j, k] / Math.Sqrt(curlx[i, j, k] * curlx[i, j, k] + curly[i, j, k] * curly[i, j, k] + curlz[i, j, k] * curlz[i, j, k]));
double costheta = Math.Cos(theta);
double...