Hi, I've been thinking in ways to convert from/to Numeric to numarray objects in a non-expensive way. For the Numeric --> numarray there is an very easy way to do that: In [45]: num=Numeric.arange(10, typecode="i") In [46]: na=numarray.array(buffer(num), typecode=num.typecode(), shape=num.shape) In [47]: na Out[47]: array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]) that creates a new numarray object without a memory copy In [48]: num[2]=3 In [49]: num Out[49]: array([0, 1, 3, 3, 4, 5, 6, 7, 8, 9],'i') In [50]: na Out[50]: array([0, 1, 3, 3, 4, 5, 6, 7, 8, 9]) i.e. both num (Numeric) and na (numarray) arrays shares the same memory. If you delete one reference: In [51]: del num the other is still accessible In [52]: na Out[52]: array([0, 1, 3, 3, 4, 5, 6, 7, 8, 9]) However, it seems that it is not so easy to go the other way, that is convert a numarray object to a Numeric without a memory copy. It seems that Numeric.array constructor get the shape from the sequence object that is passed, while numarray approach seems more sofisticated in the sense that if it detects that the first argument is a buffer sequence, you must specify the shape on the constructor. Anyone knows if building a Numeric from a buffer (specifying both type and shape) is possible (I mean, at Python level) at all?. If that would be the case, adapting libraries that use Numeric to numarray objects and vice-versa would be very easy and cheap (in terms of memory access). -- Francesc Alted