zhang yunfeng wrote: > Hi, I'm newbie to Numpy. > > When reading tutorials at > http://www.scipy.org/Tentative_NumPy_Tutorial > <http://www.scipy.org/Tentative_NumPy_Tutorial>, I found a snippet about > addition of two arrays with different shape, Does it make sense? If > array shapes are not same, why it doesn't throw out an error?
When two arrays of different shapes are operated against each other, numpy tries to "broadcast" them to a compatible shape according to certain rules. This is a fairly powerful concept, and it provides quite a lot of convenience. The following wiki page has an explanation of the broadcasting rules: http://www.scipy.org/EricsBroadcastingDoc It still refers to Numeric, numpy's predecessor, but the concepts still apply (change "Numeric" to "numpy" and "NewAxis" to "newaxis", and I believe all of the code examples will be correct). -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco _______________________________________________ Numpy-discussion mailing list [email protected] http://projects.scipy.org/mailman/listinfo/numpy-discussion
