On Monday, September 27, 1999,
ISI Software Presents .... Roger Hui
" Sparse Arrays in J "
The implementation of Sparse Arrays in J promises to open up
vast new data objects for problem solving. Data can be arranged
in exotic multi-dimensional structures that reflects its true
architecture while conserving storage.
We describe a sparse array extension to J using a representation
that "does not store zeros". One new verb $. is defined to create
and manipulate sparse arrays, and existing primitives are extended
to operate on such arrays.