Calculation of maximum order for HOA does not distinguish between even/odd numer of secondary sources

See

Lines 795 to 797 in 3ae7a9f

    
           def _max_order_circular_harmonics(N, max_order): 
        
               """Compute order of 2D HOA.""" 
        
               return N // 2 if max_order is None else max_order

This is moved to util.max_order_circular_harmonics() in #45 and changed to

return (N - 1) // 2

This should fix the issue, right?

Yes that fixes the issue!

	def _max_order_circular_harmonics(N, max_order):
	"""Compute order of 2D HOA."""
	return N // 2 if max_order is None else max_order