On 9-mar-10, at 13:21, Andrei Alexandrescu wrote:
Norbert Nemec wrote:
Multidimensional arrays are the essence of the interfaces of most
numerical libraries. Having several incompatible standards is a
major roadblock for acceptance in the numerical community.
I'm not so sure about that. I was very enthusiastic about defining
an infrastructure of arbitary-dimensional arrays, and did a little
research about it. It turns out the applicability of N-dimensional
arrays falls off a cliff when N > 3. In turn, this is because high-
dimensional space are weird - an N-dimensional space is not just
like a 3-dimensional one, only with more dimensions; it's a
downright weird beast.
yes and for dense storage, and may operations, the cost is exponential
in N, so that one normally doesn't really want to go beyond 3. Still I
did need up to 3, and well if you go with dense storage, up to 3 or up
to N is more or less the same amount f code if you use templates...
But for non dense storage it gets messy really quick because design
choices really influence the api that one can use efficiently.
Fawzi
