On Fri, Jun 5, 2009 at 1:33 PM, Geoffrey Ely
On Jun 5, 2009, at 10:18 AM, josef.pktd@gmail.com wrote:
I'm only using arrays for consistency, but my econometrics code is filled with arr[np.newaxis,:] .
arr[None,:] is a lot cleaner in my opinion, especially when using "numpy" as the namespace.
It took me a long time to figure out that None and np.newaxis do the same thing. I find newaxis more descriptive and mostly stick to it. When I started looking at numpy, I was always wondering what these "None"s were doing in the code. just one more useful trick to preserve dimension, using slices instead of index avoids arr[None,:], but requires more thinking. Josef
X matrix([[1, 0], [1, 1]]) Y array([[1, 0], [1, 1]])
X[0,:].shape == Y[0:1,:].shape True X[0,:] == Y[0:1,:] matrix([[ True, True]], dtype=bool)
-Geoff