code: def logvol_prefactor(n, p=2.):
      
  
      p *= 1.  # convert to float in case user inputs an integer
      lnf = (n * np.log(2.) + n * special.gammaln(1./p + 1.) -
             special.gammaln(n/p + 1))
  
      return lnf
docs: Returns the ln(volume constant) for an `n`-dimensional sphere with an
      :math:`L^p` norm. The constant is defined as::
  
          lnf = n * ln(2.) + n * LogGamma(1./p + 1) - LogGamma(n/p + 1.)
  
      By default the `p=2.` norm is used (i.e. the standard Euclidean norm).