2009/7/29 Ernest Adrogué <[email protected]>: > Hello, > > Suppose I want to store some data (a non-negative integer) > related to an "event" involving two entities. It occurs to me that > the way to do it is using a 2-d array, like a table: > > For example: > > a b c > a 1 > b 2 0 > c 5 > > in the event 'b-a' the data is 2, and in the event 'c-a' is 5, etc. > > Now, I need to be able to differentiate between 0 and 'no data'. > I know I could use a number like -1, but this would affect arithmetic > operations on the array, and also I need that indexing one such > location with no data returns an empty array. > > Is it possible to do this with the standard array class?
Not really. Use masked arrays. Or use a dictionary. -- 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://mail.scipy.org/mailman/listinfo/numpy-discussion
