Questions about DownValues which specify function definitions for symbols.
14
votes
5answers
762 views
The difference between 0. and 0
I have a function for which 0 is a special case:
f[A___, 0, B___] := 0
But since I am doing numerics, sometimes in the course ...
9
votes
1answer
151 views
Selectively clear DownValues
How can I clear a subset of a symbol's DownValues ?
For example, suppose I have created some DownValues for $f$ like this:
...
7
votes
2answers
210 views
How to get the list of defined values for an indexed variable?
I would like a table with rational indexes - thus it would be practical to use a dictionary, which, in Mathematica are implemented with the indexed variables. I would like to be able to do:
...
