| Copyright | (c) Brent Yorgey 2010 |
|---|---|
| License | BSD-style (see LICENSE) |
| Maintainer | byorgey@cis.upenn.edu |
| Stability | experimental |
| Safe Haskell | None |
| Language | Haskell2010 |
Math.Combinatorics.Species.Labeled
Contents
Description
An interpretation of species as exponential generating functions, which count labeled structures.
Documentation
labeled :: EGF -> [Integer] Source #
Extract the coefficients of an exponential generating function as
a list of Integers. Since EGF is an instance of Species, the
idea is that labeled can be applied directly to an expression
of the species DSL. In particular, is the
number of labeled labeled s !! ns-structures on an underlying set of size n
(note that is guaranteed to be an infinite list).
For example:labeled s
> take 10 $ labeled octopi [0,1,3,14,90,744,7560,91440,1285200,20603520]
gives the number of labeled octopi on 0, 1, 2, 3, ... 9 labels.
labelled :: EGF -> [Integer] Source #
A synonym for labeled, since both spellings are acceptable and
it's annoying to have to remember which is correct.