On Wed, Jul 29, 2015 at 1:07 PM, Neal Becker wrote:

np.uint64(-1)+0 Out[36]: 1.8446744073709552e+19

I often work on signal processing requiring bit-exact integral arithmetic. Promoting to float is not helpful - I don't understand the logic of the above example.

See this thread: http://mail.scipy.org/pipermail/numpy-discussion/2015-July/073196.html Cast your 0 to a uint64 or other unsigned int type to avoid this. -- Robert Kern