Fast check for NaN in NumPy

Question

I\'m looking for the fastest way to check for the occurrence of NaN (np.nan) in a NumPy array X. np.isnan(X) is out of the question, since

Answer 1

1. use .any()

   if numpy.isnan(myarray).any()

2. numpy.isfinite maybe better than isnan for checking

   if not np.isfinite(prop).all()