Fri May 24 15:50:01 EDT 2013


What is the basic idea?  DSP is about computations on a grid.  There
are different ways of constructing grids.  What we're interested in is
local context: given a point on a grid, there is a way to get to a
neighbouring point.

One limitiation is important: the time dimension is special.  If the
time dimension is causal (computations never refer to the future) it
is possible to re-arrange the computations in such a way that they
take the form of a state space model.

The key point is to be able to separate the description of grid
computations and their dependencies, from an actual implementation as

It's probably time to take a look again at APL and J.