comparing numpy arrays containing NaN

Question

For my unittest, I want to check if two arrays are identical. Reduced example:

a = np.array([1, 2, np.NaN])
b = np.array([1, 2, np.NaN])
if np.all(a==b):
          


        

Answer 1

You could use numpy masked arrays, mask the NaN values and then use numpy.ma.all or numpy.ma.allclose:

http://docs.scipy.org/doc/numpy/reference/generated/numpy.ma.all.html

http://docs.scipy.org/doc/numpy/reference/generated/numpy.ma.allclose.html

For example:

a=np.array([1, 2, np.NaN])
b=np.array([1, 2, np.NaN])
np.ma.all(np.ma.masked_invalid(a) == np.ma.masked_invalid(b)) #True