combinat-0.2.10.1: Generate and manipulate various combinatorial objects.
Safe HaskellSafe-Inferred
LanguageHaskell2010

Math.Combinat.Partitions.Skew

Description

Skew partitions.

Skew partitions are the difference of two integer partitions, denoted by lambda/mu.

For example

mkSkewPartition (Partition [9,7,3,2,2,1] , Partition [5,3,2,1])

creates the skew partition (9,7,3,2,2,1) / (5,3,2,1), which looks like

Synopsis

Basics

newtype SkewPartition Source #

A skew partition lambda/mu is internally represented by the list [ (mu_i , lambda_i-mu_i) | i<-[1..n] ]

Constructors

SkewPartition [(Int, Int)] 

mkSkewPartition :: (Partition, Partition) -> SkewPartition Source #

mkSkewPartition (lambda,mu) creates the skew partition lambda/mu. Throws an error if mu is not a sub-partition of lambda.

safeSkewPartition :: (Partition, Partition) -> Maybe SkewPartition Source #

Returns Nothing if mu is not a sub-partition of lambda.

skewPartitionWeight :: SkewPartition -> Int Source #

The weight of a skew partition is the weight of the outer partition minus the the weight of the inner partition (that is, the number of boxes present).

normalizeSkewPartition :: SkewPartition -> SkewPartition Source #

This function "cuts off" the "uninteresting parts" of a skew partition

fromSkewPartition :: SkewPartition -> (Partition, Partition) Source #

Returns the outer and inner partition of a skew partition, respectively:

mkSkewPartition . fromSkewPartition == id

outerPartition :: SkewPartition -> Partition Source #

The lambda part of lambda/mu

innerPartition :: SkewPartition -> Partition Source #

The mu part of lambda/mu

dualSkewPartition :: SkewPartition -> SkewPartition Source #

The dual skew partition (that is, the mirror image to the main diagonal)

skewPartitionElements :: SkewPartition -> [(Int, Int)] Source #

See "partitionElements"

Listing skew partitions

skewPartitionsWithOuterShape :: Partition -> Int -> [SkewPartition] Source #

Lists all skew partitions with the given outer shape and given (skew) weight

allSkewPartitionsWithOuterShape :: Partition -> [SkewPartition] Source #

Lists all skew partitions with the given outer shape and any (skew) weight

skewPartitionsWithInnerShape :: Partition -> Int -> [SkewPartition] Source #

Lists all skew partitions with the given inner shape and given (skew) weight

ASCII