docs: def check_array_or_list(input):
      """Return 1D ndarray, if input can be converted and elements are
      non-negative."""
      if type(input) != np.ndarray:
          if type(input) == list:
              output = np.array(input)
          else:
              raise TypeError('Expecting input type as ndarray or list.')
      else:
          output = input
  
      if output.ndim != 1:
          raise ValueError('Input array must have 1 dimension.')
  
      if np.sum(output < 0.) > 0:
              raise ValueError("Input array values cannot be negative.")
  
      return output