The problem can not be solved until after you have specified the problem. But, yes, the problem is solvable. And the sparse array approach is just one of the possible tools for solving it.
But, yes, also, there can be problems with calculations on sparse arrays. Anything real can have problems. Thanks, -- Raul On Thu, Sep 21, 2017 at 6:51 AM, Erling Hellenäs <[email protected]> wrote: > I never used sparse arrays. An empty element means missing data? That seems > useful. Does that mean the problem is solved or are float arrays preferable > to sparse arrays for some other reason? It is easy enough to make > distinctions between NaNs, positive/negative infinity, missing data and > valid data? There are no problems with calculations on sparse arrays? > /Erling > > > Den 2017-09-21 kl. 03:29, skrev Raul Miller: >> >> That wouldn't make a lot of sense, though, for classic operations on >> sparse matrices (like +/ .*), would it? >> >> That said, it might sense to leave 0 as the sparse element, and then >> use the distinction between sparse zeros and dense zeros to track >> undefined values... >> >> Thanks, >> > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
