code: def rc2lar(k):
      
      assert numpy.isrealobj(k), 'Log area ratios not defined for complex reflection coefficients.'
      if max(numpy.abs(k)) >= 1:
          raise ValueError('All reflection coefficients should have magnitude less than unity.')
  
      # Use the relation, atanh(x) = (1/2)*log((1+k)/(1-k))
      return -2 * numpy.arctanh(-numpy.array(k))
docs: Convert reflection coefficients to log area ratios.
  
      :param k: reflection coefficients
      :return: inverse sine parameters
  
      The log area ratio is defined by G = log((1+k)/(1-k)) , where the K
      parameter is the reflection coefficient.
  
      .. seealso:: :func:`lar2rc`, :func:`rc2poly`, :func:`rc2ac`, :func:`rc2ic`.
  
      :References:
         [1] J. Makhoul, "Linear Prediction: A Tutorial Review," Proc. IEEE, Vol.63, No.4, pp.561-580, Apr 1975.