[Numpy-discussion] Irregular arrays

rw679aq02 at sneakemail.com rw679aq02 at sneakemail.com
Wed Aug 30 03:21:05 CDT 2006


Travis,

A sparse matrix is a different animal serving a different purpose, i.e.,
solution of linear systems.  Those storage formats are geared for that
application: upper diagonal, block diagonal, stripwise, etc.

To be more specific: here tight numerical arrays are presumably
discussed.  Python and other languages could define an "irregular list
of irregular lists" or "aggregation of objects" configuration.  Probably
Lisp would be better for that.  But it is not my driving interest.  My
interest is packed storage minimizing memory consumption and access
time, with bonus points for integration with numerical recipes and
element-wise operations.

Again, actual demonstration would be appreciated.  I selected an example
with minimal deviation from a regular array to simplify things.  The
shape is essentially a cube with a planar cut across one corner.  The
Mathematica code shows it is very easy to define in that language.  (I
am not sure whether it is tightly packed but it shows O(N) performance
graphs.)




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