[Numpy-discussion] Irregular arrays

[rw679aq02 at sneakemail.com]

Many problems are best solved with irregular array structures.  These
are aggregations not having a rectangular shape.  To motivate, here's
one example,

   http://lambda-the-ultimate.org/files/HammingNumbersDeclarative.7z
         - from http://lambda-the-ultimate.org/node/608#comment-5746

Irregularity here changes an O(N^3) solution to O(N).  (The file format
is a 7zip archive with a MathReader file inside, readable in Windows or
Unix with free software.)

These cases also arise in simulations where physical geometry determines
array shape.  Here memory consumption is the minimization goal that
makes irregularity desirable.  The access function will return NaN or
zero for out-of-bounds requests.  There is no need to consume memory
storing NaNs and zeros.

Please advise how much support numpy/Scipy has for these structures, if
any, including future plans.  If support exists, could you kindly supply
a Scipy declaration matching the first example.

Thank you very much.