code: def nsphere_volume(radius, ndim):
      return pi ** (ndim / 2.0) / gamma(ndim / 2.0 + 1) * radius**ndim
  
imports: import numpy
  from math import gamma, pi, exp
label_desc: Use image node_id 3 for calling a global function with example usage: nsphere_volume(radius, ndim) and returns: unknown