CCTK_REAL x0 "Position of black hole"
{
  *:* :: ""
} 0.0

CCTK_REAL y0 "Position of black hole"
{
  *:* :: ""
} 0.0
CCTK_REAL z0 "Position of black hole"
{
  *:* :: ""
} 0.0

  const T r = smooth(sqrt(pow2(expand(x)) + pow2(expand(y)) + pow2(expand(z))));

  const T r = smooth(
      sqrt(pow2(expand(x - x0)) + pow2(expand(y - y0)) + pow2(expand(z - z0))));

  const T r = smooth(sqrt(pow2(expand(x)) + pow2(expand(y)) + pow2(expand(z))));

  const T r = smooth(
      sqrt(pow2(expand(x - x0)) + pow2(expand(y - y0)) + pow2(expand(z - z0))));