Package 'jack'

Title: Jack, Zonal, Schur, and Other Symmetric Polynomials
Description: Schur polynomials appear in combinatorics and zonal polynomials appear in random matrix theory. They are particular cases of Jack polynomials. This package allows to compute these polynomials and other symmetric multivariate polynomials: flagged Schur polynomials, factorial Schur polynomials, t-Schur polynomials, Hall-Littlewood polynomials, Macdonald polynomials, and modified Macdonald polynomials. In addition, it can compute the Kostka-Jack numbers, the Kostka-Foulkes polynomials, the Kostka-Macdonald polynomials, and the Hall polynomials. Mainly based on Demmel & Koev's paper (2006) <doi:10.1090/S0025-5718-05-01780-1> and Macdonald's book (1995) <doi:10.1093/oso/9780198534891.003.0001>.
Authors: Stéphane Laurent [aut, cre]
Maintainer: Stéphane Laurent <[email protected]>
License: GPL-3
Version: 6.1.0
Built: 2024-11-27 06:56:01 UTC
Source: CRAN

Help Index


Evaluation of elementary symmetric functions

Description

Evaluates an elementary symmetric function.

Usage

ESF(x, lambda)

Arguments

x

a numeric vector or a bigq vector

lambda

an integer partition, given as a vector of decreasing integers

Value

A number if x is numeric, a bigq rational number if x is a bigq vector.

Examples

x <- c(1, 2, 5/2)
lambda <- c(3, 1)
ESF(x, lambda)
library(gmp)
x <- c(as.bigq(1), as.bigq(2), as.bigq(5,2))
ESF(x, lambda)

Factorial Schur polynomial

Description

Computes a factorial Schur polynomial.

Usage

factorialSchurPol(n, lambda, a)

Arguments

n

number of variables

lambda

integer partition

a

vector of bigq numbers, or vector of elements coercible to bigq numbers; this vector corresponds to the sequence denoted by aa in the reference paper, section 6th Variation (in this paper aa is a doubly infinite sequence, but in the case of a non-skew partition, the non-positive indices of this sequence are not involved); the length of this vector must be large enough (an error will be thrown if it is too small) but it is not easy to know the minimal possible length

Value

A qspray polynomial.

References

I.G. Macdonald. Schur functions: theme and variations. Publ. IRMA Strasbourg, 1992.

Examples

# for a=c(0, 0, ...), the factorial Schur polynomial is the Schur polynomial
n <- 3
lambda <- c(2, 2, 2)
a <- c(0, 0, 0, 0)
factorialSchurPoly <- factorialSchurPol(n, lambda, a)
schurPoly <- SchurPol(n, lambda)
factorialSchurPoly == schurPoly # should be TRUE

Flagged Schur polynomial

Description

Computes a flagged Schur polynomial (which is not symmetric in general). See Chains in the Bruhat order for the definition.

Usage

flaggedSchurPol(lambda, a, b)

Arguments

lambda

integer partition

a, b

lower bounds and upper bounds, weakly increasing vectors of integers; lambda, a and b must have the same length

Value

A qspray polynomial.

Examples

lambda <- c(3, 2, 2)
n <- 3
a <- c(1, 1, 1); b <- c(n, n, n)
flaggedPoly <- flaggedSchurPol(lambda, a, b)
poly <- SchurPol(n, lambda)
flaggedPoly == poly # should be TRUE

Flagged skew Schur polynomial

Description

Computes a flagged skew Schur polynomial (which is not symmetric in general). See Schur polynomials (flagged) for the definition.

Usage

flaggedSkewSchurPol(lambda, mu, a, b)

Arguments

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

a, b

lower bounds and upper bounds, weakly increasing vectors of integers; lambda, a and b must have the same length

Value

A qspray polynomial.

Examples

lambda <- c(3, 2, 2); mu <- c(2, 1)
n <- 3
a <- c(1, 1, 1); b <- c(n, n, n)
flaggedPoly <- flaggedSkewSchurPol(lambda, mu, a, b)
poly <- SkewSchurPol(n, lambda, mu)
flaggedPoly == poly # should be TRUE

Hall-Littlewood polynomial

Description

Hall-Littlewood polynomial of a given partition.

Usage

HallLittlewoodPol(n, lambda, which = "P")

Arguments

n

number of variables

lambda

integer partition

which

which Hall-Littlewood polynomial, "P" or "Q"

Value

The Hall-Littlewood polynomial in n variables of the integer partition lambda. This is a symbolicQspray polynomial with a unique parameter usually denoted by tt and its coefficients are polynomial in this parameter. When substituting tt with 00 in the Hall-Littlewood PP-polynomials, one obtains the Schur polynomials.


Hall polynomials

Description

Hall polynomials gμ,νλ(t)g^{\lambda}_{\mu,\nu}(t) for given integer partitions μ\mu and ν\nu.

Usage

HallPolynomials(mu, nu)

Arguments

mu, nu

integer partitions

Value

A list of lists. Each of these lists has two elements: an integer partition λ\lambda in the field lambda, and a univariate qspray polynomial in the field polynomial, the Hall polynomial gμ,νλ(t)g^{\lambda}_{\mu,\nu}(t). Every coefficient of a Hall polynomial is an integer.

Note

This function is slow.

Examples

HallPolynomials(c(2, 1), c(1, 1))

Evaluation of Jack polynomial - C++ implementation

Description

Evaluates a Jack polynomial.

Usage

Jack(x, lambda, alpha)

Arguments

x

values of the variables, a vector of bigq numbers, or a vector that can be coerced as such (e.g. c("2", "5/3"))

lambda

an integer partition, given as a vector of decreasing integers

alpha

rational number, given as a string such as "2/3" or as a bigq number

Value

A bigq number.

Examples

Jack(c("1", "3/2", "-2/3"), lambda = c(3, 1), alpha = "1/4")

Symmetric polynomial in terms of Jack polynomials

Description

Expression of a symmetric polynomial as a linear combination of Jack polynomials.

Usage

JackCombination(qspray, alpha, which = "J", check = TRUE)

Arguments

qspray

a qspray object or a symbolicQspray object defining a symmetric polynomial

alpha

Jack parameter, must be coercible to a bigq number

which

which Jack polynomials, "J", "P", "Q" or "C"

check

Boolean, whether to check the symmetry of qspray

Value

A list defining the combination. Each element of this list is a list with two elements: coeff, which is a bigq number if qspray is a qspray polynomial or a ratioOfQsprays if qspray is a symbolicQspray polynomial, and the second element of the list is lambda, an integer partition; then this list corresponds to the term coeff * JackPol(n, lambda, alpha, which), where n is the number of variables in the symmetric polynomial qspray.


Jack polynomial - C++ implementation

Description

Returns a Jack polynomial.

Usage

JackPol(n, lambda, alpha, which = "J")

Arguments

n

number of variables, a positive integer

lambda

an integer partition, given as a vector of decreasing integers

alpha

rational number, given as a string such as "2/3" or as a bigq number

which

which Jack polynomial, "J", "P", "Q", or "C"

Value

A qspray multivariate polynomial.

Examples

JackPol(3, lambda = c(3, 1), alpha = "2/5")

Jack polynomial

Description

Returns the Jack polynomial.

Usage

JackPolR(n, lambda, alpha, algorithm = "DK", basis = "canonical", which = "J")

Arguments

n

number of variables, a positive integer

lambda

an integer partition, given as a vector of decreasing integers

alpha

parameter of the Jack polynomial, a number, possibly (and preferably) a bigq rational number

algorithm

the algorithm used, either "DK" or "naive"

basis

the polynomial basis for algorithm = "naive", either "canonical" or "MSF" (monomial symmetric functions); for algorithm = "DK" the canonical basis is always used and this parameter is ignored

which

which Jack polynomial, "J", "P" or "Q"; this argument is taken into account only if alpha is a bigq number and algorithm = "DK"

Value

A mvp multivariate polynomial (see mvp-package), or a qspray multivariate polynomial if alpha is a bigq rational number and algorithm = "DK", or a character string if basis = "MSF".

Examples

JackPolR(3, lambda = c(3,1), alpha = gmp::as.bigq(2,3),
                  algorithm = "naive")
JackPolR(3, lambda = c(3,1), alpha = 2/3, algorithm = "DK")
JackPolR(3, lambda = c(3,1), alpha = gmp::as.bigq(2,3), algorithm = "DK")
JackPolR(3, lambda = c(3,1), alpha= gmp::as.bigq(2,3),
        algorithm = "naive", basis = "MSF")
# when the Jack polynomial is a `qspray` object, you can
# evaluate it with `qspray::evalQspray`:
jack <- JackPolR(3, lambda = c(3, 1), alpha = gmp::as.bigq(2))
evalQspray(jack, c("1", "1/2", "3"))

Evaluation of Jack polynomials

Description

Evaluates a Jack polynomial.

Usage

JackR(x, lambda, alpha, algorithm = "DK")

Arguments

x

numeric or complex vector or bigq vector

lambda

an integer partition, given as a vector of decreasing integers

alpha

ordinary number or bigq rational number

algorithm

the algorithm used, either "DK" (Demmel-Koev) or "naive"

Value

A numeric or complex scalar or a bigq rational number.

References

  • I.G. Macdonald. Symmetric Functions and Hall Polynomials. Oxford Mathematical Monographs. The Clarendon Press Oxford University Press, New York, second edition, 1995.

  • J. Demmel & P. Koev. Accurate and efficient evaluation of Schur and Jack functions. Mathematics of computations, vol. 75, n. 253, 223-229, 2005.

  • Jack polynomials. https://www.symmetricfunctions.com/jack.htm

See Also

JackPolR

Examples

lambda <- c(2,1,1)
JackR(c(1/2, 2/3, 1), lambda, alpha = 3)
# exact value:
JackR(c(gmp::as.bigq(1,2), gmp::as.bigq(2,3), gmp::as.bigq(1)), lambda,
     alpha = gmp::as.bigq(3))

Jack polynomial with symbolic Jack parameter

Description

Returns the Jack polynomial with a symbolic Jack parameter.

Usage

JackSymPol(n, lambda, which = "J")

Arguments

n

number of variables, a positive integer

lambda

an integer partition, given as a vector of decreasing integers

which

which Jack polynomial, "J", "P", "Q", or "C"

Value

A symbolicQspray object.

Examples

JackSymPol(3, lambda = c(3, 1))

Kostka-Foulkes polynomial

Description

Kostka-Foulkes polynomial for two given partitions.

Usage

KostaFoulkesPolynomial(lambda, mu)

Arguments

lambda, mu

integer partitions; in order for the Kostka-Foulkes polynomial to be non-zero, a necessary condition is that lambda and mu have the same weight; more precisely, mu must be dominated by lambda

Value

The Kostka-Foulkes polynomial associated to lambda and mu. This is a univariate qspray polynomial whose value at 1 is the Kostka number associated to lambda and mu.


Kostka-Jack numbers with a given Jack parameter

Description

Kostka numbers with Jack parameter, or Kostka-Jack numbers, for partitions of a given weight and a given Jack parameter.

Usage

KostkaJackNumbers(n, alpha = "1")

Arguments

n

positive integer, the weight of the partitions

alpha

the Jack parameter, a bigq number or an object coercible to a bigq number

Details

The Kostka-Jack number Kλ,μ(α)K_{\lambda,\mu}(\alpha) is the coefficient of the monomial symmetric polynomial mμm_\mu in the expression of the PP-Jack polynomial Pλ(α)P_\lambda(\alpha) as a linear combination of monomial symmetric polynomials. For α=1\alpha=1 it is the ordinary Kostka number.

Value

The matrix of the Kostka-Jack numbers Kλ,μ(α)K_{\lambda,\mu}(\alpha) given as character strings representing integers or fractions. The row names of this matrix encode the partitions λ\lambda and the column names encode the partitions μ\mu

See Also

KostkaJackNumbersWithGivenLambda, symbolicKostkaJackNumbers, skewKostkaJackNumbers.

Examples

KostkaJackNumbers(4)

Kostka-Jack numbers with a given partition λ\lambda

Description

Kostka numbers with Jack parameter, or Kostka-Jack numbers Kλ,μ(α)K_{\lambda,\mu}(\alpha) for a given Jack parameter α\alpha and a given integer partition λ\lambda.

Usage

KostkaJackNumbersWithGivenLambda(lambda, alpha, output = "vector")

Arguments

lambda

integer partition

alpha

the Jack parameter, a bigq number or anything coercible to a bigq number

output

the format of the output, either "vector" or "list"

Details

The Kostka-Jack number Kλ,μ(α)K_{\lambda,\mu}(\alpha) is the coefficient of the monomial symmetric polynomial mμm_\mu in the expression of the PP-Jack polynomial Pλ(α)P_\lambda(\alpha) as a linear combination of monomial symmetric polynomials. For α=1\alpha=1 it is the ordinary Kostka number.

Value

If output="vector", this function returns a named vector. This vector is made of the non-zero (i.e. positive) Kostka-Jack numbers Kλ,μ(α)K_{\lambda,\mu}(\alpha) given as character strings and its names encode the partitions μ\mu. If ouput="list", this function returns a list of lists. Each of these lists has two elements. The first one is named mu and is an integer partition, and the second one is named value and is a bigq rational number, the Kostka-Jack number Kλ,μ(α)K_{\lambda,\mu}(\alpha).

See Also

KostkaJackNumbers, symbolicKostkaJackNumbersWithGivenLambda.

Examples

KostkaJackNumbersWithGivenLambda(c(3, 2), alpha = "2")

Littlewood-Richardson rule for multiplication

Description

Expression of the product of two Schur polynomials as a linear combination of Schur polynomials.

Usage

LRmult(mu, nu, output = "dataframe")

Arguments

mu, nu

integer partitions, given as vectors of decreasing integers

output

the type of the output, "dataframe" or "list"

Value

This computes the expression of the product of the two Schur polynomials associated to mu and nu as a linear combination of Schur polynomials. If output="dataframe", the output is a dataframe with two columns: the column coeff gives the coefficients of this linear combination, these are positive integers, and the column lambda gives the partitions defining the Schur polynomials of this linear combination as character strings, e.g. the partition c(4, 3, 1) is encoded by the character string "[4, 3, 1]". If output="list", the output is a list of lists with two elements. Each of these lists with two elements corresponds to a term of the linear combination: the first element, named coeff, is the coefficient, namely the Littlewood-Richardson coefficient cμ,νλc^{\lambda}_{\mu,\nu}, where λ\lambda is the integer partition given in the second element of the list, named lambda, which defines the Schur polynomial of the linear combination.

Examples

library(jack)
mu <- c(2, 1)
nu <- c(3, 2, 1)
LR <- LRmult(mu, nu, output = "list")
LRterms <- lapply(LR, function(lr) {
  lr[["coeff"]] * SchurPol(3, lr[["lambda"]])
})
smu_times_snu <- Reduce(`+`, LRterms)
smu_times_snu == SchurPol(3, mu) * SchurPol(3, nu) # should be TRUE

Littlewood-Richardson rule for skew Schur polynomial

Description

Expression of a skew Schur polynomial as a linear combination of Schur polynomials.

Usage

LRskew(lambda, mu, output = "dataframe")

Arguments

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

output

the type of the output, "dataframe" or "list"

Value

This computes the expression of the skew Schur polynomial associated to the skew partition defined by lambda and mu as a linear combination of Schur polynomials. Every coefficient of this linear combination is a positive integer, a so-called Littlewood-Richardson coefficient. If output="dataframe", the output is a dataframe with two columns: the column coeff gives the coefficients of this linear combination, and the column nu gives the partitions defining the Schur polynomials of this linear combination as character strings, e.g. the partition c(4, 3, 1) is given by "[4, 3, 1]". If output="list", the output is a list of lists with two elements. Each of these lists with two elements corresponds to a term of the linear combination: the first element, named coeff, is the coefficient, namely the Littlewood-Richardson coefficient cμ,νλc^{\lambda}_{\mu,\nu}, where ν\nu is the integer partition given in the second element of the list, named nu, which defines the Schur polynomial of the linear combination.

Examples

library(jack)
LRskew(lambda = c(4, 2, 1), mu = c(3, 1))

Macdonald polynomial

Description

Returns the Macdonald polynomial associated to the given integer partition.

Usage

MacdonaldPol(n, lambda, which = "P")

Arguments

n

number of variables, a positive integer

lambda

integer partition

which

which Macdonald polynomial, "P", "Q", or "J"

Value

A symbolicQspray multivariate polynomial, the Macdonald polynomial associated to the integer partition lambda. It has two parameters usually denoted by qq and tt. Substituting qq with 00 yields the Hall-Littlewood polynomials.


Modified Macdonald polynomial

Description

Returns the modified Macdonald polynomial associated to a given integer partition.

Usage

modifiedMacdonaldPol(n, mu)

Arguments

n

number of variables, a positive integer

mu

integer partition

Value

A symbolicQspray multivariate polynomial, the modified Macdonald polynomial associated to the integer partition mu. It has two parameters and its coefficients are polynomials in these parameters.


Evaluation of monomial symmetric functions

Description

Evaluates a monomial symmetric function.

Usage

MSF(x, lambda)

Arguments

x

a numeric vector or a bigq vector

lambda

an integer partition, given as a vector of decreasing integers

Value

A number if x is numeric, a bigq rational number if x is a bigq vector.

Examples

x <- c(1, 2, 5/2)
lambda <- c(3, 1)
MSF(x, lambda)
library(gmp)
x <- c(as.bigq(1), as.bigq(2), as.bigq(5,2))
MSF(x, lambda)

qt-Kostka polynomials

Description

qt-Kostka polynomials, aka Kostka-Macdonald polynomials.

Usage

qtKostkaPolynomials(mu)

Arguments

mu

integer partition

Value

A list. The qt-Kostka polynomials are usually denoted by Kλ,μ(q,t)K_{\lambda, \mu}(q, t) where qq and tt denote the two variables and λ\lambda and μ\mu are two integer partitions. One obtains the Kostka-Foulkes polynomials by substituting qq with 00. For a given partition μ\mu, the function returns the polynomials Kλ,μ(q,t)K_{\lambda, \mu}(q, t) as qspray objects for all partitions λ\lambda of the same weight as μ\mu. The generated list is a list of lists with two elements: the integer partition λ\lambda and the polynomial.


Skew qt-Kostka polynomials

Description

Skew qt-Kostka polynomials associated to a given skew partition.

Usage

qtSkewKostkaPolynomials(lambda, mu)

Arguments

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

Value

A list. The skew qt-Kostka polynomials are usually denoted by Kλ/μ,ν(q,t)K_{\lambda/\mu, \nu}(q, t) where qq and tt denote the two variables, λ\lambda and μ\mu are the two integer partitions defining the skew partition, and ν\nu is an integer partition. One obtains the skew Kostka-Foulkes polynomials by substituting qq with 00. For given partitions λ\lambda and μ\mu, the function returns the polynomials Kλ/μ,ν(q,t)K_{\lambda/\mu, \nu}(q, t) as qspray objects for all partitions ν\nu of the same weight as the skew partition. The generated list is a list of lists with two elements: the integer partition ν\nu and the polynomial.


Evaluation of Schur polynomial - C++ implementation

Description

Evaluates a Schur polynomial. The Schur polynomials are the Jack PP-polynomials with Jack parameter α=1\alpha=1.

Usage

Schur(x, lambda)

Arguments

x

values of the variables, a vector of bigq numbers, or a vector that can be coerced as such (e.g. c("2", "5/3"))

lambda

an integer partition, given as a vector of decreasing integers

Value

A bigq number.

Examples

Schur(c("1", "3/2", "-2/3"), lambda = c(3, 1))

Symmetric polynomial in terms of the Schur polynomials

Description

Expression of a symmetric polynomial as a linear combination of some Schur polynomials.

Usage

SchurCombination(qspray, check = TRUE)

Arguments

qspray

a qspray object defining a symmetric polynomial

check

Boolean, whether to check the symmetry of qspray

Value

A list defining the combination. Each element of this list is a list with two elements: coeff, a bigq number, and lambda, an integer partition; then this list corresponds to the term coeff * SchurPol(n, lambda), where n is the number of variables in the symmetric polynomial.

See Also

JackCombination.


Schur polynomial - C++ implementation

Description

Returns a Schur polynomial. The Schur polynomials are the Jack PP-polynomials with Jack parameter α=1\alpha=1.

Usage

SchurPol(n, lambda)

Arguments

n

number of variables, a positive integer

lambda

an integer partition, given as a vector of decreasing integers

Value

A qspray multivariate polynomial.

Examples

( schur <- SchurPol(3, lambda = c(3, 1)) )
schur == JackPol(3, lambda = c(3, 1), alpha = "1", which = "P")

Schur polynomial

Description

Returns the Schur polynomial.

Usage

SchurPolR(n, lambda, algorithm = "DK", basis = "canonical", exact = TRUE)

Arguments

n

number of variables, a positive integer

lambda

an integer partition, given as a vector of decreasing integers

algorithm

the algorithm used, either "DK" or "naive"

basis

the polynomial basis for algorithm = "naive", either "canonical" or "MSF" (monomial symmetric functions); for algorithm = "DK" the canonical basis is always used and this parameter is ignored

exact

logical, whether to use exact arithmetic

Value

A mvp multivariate polynomial (see mvp-package), or a qspray multivariate polynomial if exact = TRUE and algorithm = "DK", or a character string if basis = "MSF".

Examples

SchurPolR(3, lambda = c(3,1), algorithm = "naive")
SchurPolR(3, lambda = c(3,1), algorithm = "DK")
SchurPolR(3, lambda = c(3,1), algorithm = "DK", exact = FALSE)
SchurPolR(3, lambda = c(3,1), algorithm = "naive", basis = "MSF")

Evaluation of Schur polynomials

Description

Evaluates a Schur polynomial.

Usage

SchurR(x, lambda, algorithm = "DK")

Arguments

x

numeric or complex vector or bigq vector

lambda

an integer partition, given as a vector of decreasing integers

algorithm

the algorithm used, either "DK" (Demmel-Koev) or "naive"

Value

A numeric or complex scalar or a bigq rational number.

References

J. Demmel & P. Koev. Accurate and efficient evaluation of Schur and Jack functions. Mathematics of computations, vol. 75, n. 253, 223-229, 2005.

See Also

SchurPolR

Examples

x <- c(2,3,4)
SchurR(x, c(2,1,1))
prod(x) * sum(x)

Skew factorial Schur polynomial

Description

Computes the skew factorial Schur polynomial associated to a given skew partition.

Usage

SkewFactorialSchurPol(n, lambda, mu, a, i0)

Arguments

n

number of variables

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

a

vector of bigq numbers, or vector of elements coercible to bigq numbers; this vector corresponds to the sequence denoted by aa in the reference paper, section 6th Variation (in this paper aa is a doubly infinite sequence, but only a finite number of indices are not involved); the length of this vector must be large enough (an error will be thrown if it is too small) but it is not easy to know the minimal possible length

i0

positive integer, the index of a that must be considered as the zero index of the sequence denoted by aa in the reference paper

Value

A qspray polynomial.

References

I.G. Macdonald. Schur functions: theme and variations. Publ. IRMA Strasbourg, 1992.

Examples

# for a=c(0, 0, ...), the skew factorial Schur polynomial is the
# skew Schur polynomial; let's check
n <- 4
lambda <- c(3, 3, 2, 2); mu <- c(2, 2)
a <- rep(0, 9)
i0 <- 3
skewFactorialSchurPoly <- SkewFactorialSchurPol(n, lambda, mu, a, i0)
skewSchurPoly <- SkewSchurPol(n, lambda, mu)
skewFactorialSchurPoly == skewSchurPoly # should be TRUE

Skew Hall-Littlewood polynomial

Description

Returns the skew Hall-Littlewood polynomial associated to the given skew partition.

Usage

SkewHallLittlewoodPol(n, lambda, mu, which = "P")

Arguments

n

number of variables, a positive integer

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

which

which skew Hall-Littlewood polynomial, "P" or "Q"

Value

A symbolicQspray multivariate polynomial, the skew Hall-Littlewood polynomial associated to the skew partition defined by lambda and mu. It has a single parameter usually denoted by tt and its coefficients are polynomial in this parameter. When substituting tt with 00 in the skew Hall-Littlewood PP-polynomials, one obtains the skew Schur polynomials.

Examples

n <- 3; lambda <- c(3, 2, 1); mu <- c(1, 1)
skewHLpoly <- SkewHallLittlewoodPol(n, lambda, mu)
skewSchurPoly <- SkewSchurPol(n, lambda, mu)
substituteParameters(skewHLpoly, 0) == skewSchurPoly # should be TRUE

Skew Jack polynomial

Description

Computes a skew Jack polynomial with a given Jack parameter.

Usage

SkewJackPol(n, lambda, mu, alpha, which = "J")

Arguments

n

positive integer, the number of variables

lambda

outer integer partition of the skew partition

mu

inner integer partition of the skew partition; it must be a subpartition of lambda

alpha

the Jack parameter, any object coercible to a bigq number

which

which skew Jack polynomial, "J", "P", "Q" or "C"

Value

A qspray polynomial.

See Also

SkewJackSymPol.

Examples

SkewJackPol(3, c(3,1), c(2), "2")

Skew Jack polynomial with symbolic Jack parameter

Description

Computes a skew Jack polynomial with a symbolic Jack parameter.

Usage

SkewJackSymPol(n, lambda, mu, which = "J")

Arguments

n

positive integer, the number of variables

lambda

outer integer partition of the skew partition

mu

inner integer partition of the skew partition; it must be a subpartition of lambda

which

which skew Jack polynomial, "J", "P", "Q" or "C"

Value

A symbolicQspray polynomial.

Examples

SkewJackSymPol(3, c(3,1), c(2))

Skew Kostka-Foulkes polynomial

Description

Computes a skew Kostka-Foulkes polynomial.

Usage

SkewKostkaFoulkesPolynomial(lambda, mu, nu)

Arguments

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

nu

integer partition; the condition sum(nu)==sum(lambda)-sum(mu) is necessary in order to get a non-zero polynomial

Value

The skew Kostka-Foulkes polynomial associated to the skew partitiion defined by lambda and mu and to the partition nu. This is a univariate qspray polynomial whose value at 1 is the skew Kostka number associated to the skew partition defined by lambda and mu and to the partition nu.


Skew Kostka-Jack numbers with given Jack parameter

Description

Skew Kostka-Jack numbers associated to a given skew partition and a given Jack parameter.

Usage

skewKostkaJackNumbers(lambda, mu, alpha = NULL, output = "vector")

Arguments

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

alpha

the Jack parameter, a bigq number or an object coercible to a bigq number; setting alpha=NULL is equivalent to set alpha=1

output

the format of the output, either "vector" or "list"

Details

The skew Kostka-Jack number Kλ/μ,ν(α)K_{\lambda/\mu,\nu}(\alpha) is the coefficient of the monomial symmetric polynomial mνm_\nu in the expression of the skew PP-Jack polynomial Pλ/μ(α)P_{\lambda/\mu}(\alpha) as a linear combination of monomial symmetric polynomials. For α=1\alpha=1 it is the ordinary skew Kostka number.

Value

If output="vector", the function returns a named vector. This vector is made of the non-zero skew Kostka-Jack numbers Kλ/μ,ν(α)K_{\lambda/\mu,\nu}(\alpha) given as character strings and its names encode the partitions ν\nu. If ouput="list", the function returns a list. Each element of this list is a named list with two elements: an integer partition ν\nu in the field named "nu", and the corresponding skew Kostka-Jack number Kλ/μ,ν(α)K_{\lambda/\mu,\nu}(\alpha) in the field named "value". Only the non-null skew Kostka-Jack numbers are provided by this list.

Note

The skew Kostka-Jack numbers Kλ/μ,ν(α)K_{\lambda/\mu,\nu}(\alpha) are well defined when the Jack parameter α\alpha is zero, however this function does not work with alpha=0. A possible way to get the skew Kostka-Jack numbers Kλ/μ,ν(0)K_{\lambda/\mu,\nu}(0) is to use the function symbolicSkewKostkaJackNumbers to get the skew Kostka-Jack numbers with a symbolic Jack parameter α\alpha, and then to substitute α\alpha with 00.

See Also

symbolicSkewKostkaJackNumbers.

Examples

skewKostkaJackNumbers(c(4,2,2), c(2,2))

Skew Macdonald polynomial

Description

Returns the skew Macdonald polynomial associated to the given skew partition.

Usage

SkewMacdonaldPol(n, lambda, mu, which = "P")

Arguments

n

number of variables, a positive integer

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

which

which skew Macdonald polynomial, "P", "Q" or "J"

Value

A symbolicQspray multivariate polynomial, the skew Macdonald polynomial associated to the skew partition defined by lambda and mu. It has two parameters usually denoted by qq and tt. Substituting qq with 00 yields the skew Hall-Littlewood polynomials.


Skew Schur polynomial

Description

Returns the skew Schur polynomial.

Usage

SkewSchurPol(n, lambda, mu)

Arguments

n

number of variables, a positive integer

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

Details

The computation is performed with the help of the Littlewood-Richardson rule (see LRskew).

Value

A qspray multivariate polynomial, the skew Schur polynomial associated to the skew partition defined by lambda and mu.

Examples

SkewSchurPol(3, lambda = c(3, 2, 1), mu = c(1, 1))

Symmetric polynomial in terms of symbolic Jack polynomials

Description

Expression of a symmetric polynomial as a linear combination of Jack polynomials with a symbolic Jack parameter.

Usage

symbolicJackCombination(qspray, which = "J", check = TRUE)

Arguments

qspray

a qspray object or a symbolicQspray object defining a symmetric polynomial

which

which Jack polynomials, "J", "P", "Q" or "C"

check

Boolean, whether to check the symmetry

Value

A list defining the combination. Each element of this list is a list with two elements: coeff, a bigq number, and lambda, an integer partition; then this list corresponds to the term coeff * JackSymPol(n, lambda, which), where n is the number of variables in the symmetric polynomial.


Kostka-Jack numbers with symbolic Jack parameter

Description

Kostka-Jack numbers with a symbolic Jack parameter for integer partitions of a given weight.

Usage

symbolicKostkaJackNumbers(n)

Arguments

n

positive integer, the weight of the partitions

Value

A named list of named lists of ratioOfQsprays objects. Denoting the Kostka-Jack numbers by Kλ,μ(α)K_{\lambda,\mu}(\alpha), the names of the outer list correspond to the partitions λ\lambda, and the names of the inner lists correspond to the partitions μ\mu.

See Also

KostkaJackNumbers, symbolicKostkaJackNumbersWithGivenLambda.

Examples

symbolicKostkaJackNumbers(3)

Kostka-Jack numbers with symbolic Jack parameter for a given λ\lambda

Description

Kostka-Jack numbers Kλ,μ(α)K_{\lambda,\mu}(\alpha) with a symbolic Jack parameter α\alpha for a given integer partition λ\lambda.

Usage

symbolicKostkaJackNumbersWithGivenLambda(lambda)

Arguments

lambda

integer partition

Value

A named list of ratioOfQsprays objects. The elements of this list are the Kostka-Jack numbers Kλ,μ(α)K_{\lambda,\mu}(\alpha) and its names correspond to the partitions μ\mu.

See Also

KostkaJackNumbersWithGivenLambda, symbolicKostkaJackNumbers.

Examples

symbolicKostkaJackNumbersWithGivenLambda(c(3, 1))

Skew Kostka-Jack numbers with symbolic Jack parameter

Description

Skew Kostka-Jack numbers associated to a given skew partition with a symbolic Jack parameter.

Usage

symbolicSkewKostkaJackNumbers(lambda, mu)

Arguments

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

Value

The function returns a list. Each element of this list is a named list with two elements: an integer partition ν\nu in the field named "nu", and the corresponding skew Kostka number Kλ/μ,ν(α)K_{\lambda/\mu,\nu}(\alpha) in the field named "value", a ratioOfQsprays object.

Examples

symbolicSkewKostkaJackNumbers(c(4,2,2), c(2,2))

t-Schur polynomial

Description

Returns the t-Schur polynomial associated to the given partition.

Usage

tSchurPol(n, lambda)

Arguments

n

number of variables, a positive integer

lambda

integer partition

Value

A symbolicQspray multivariate polynomial, the t-Schur polynomial associated to lambda. It has a single parameter usually denoted by tt and its coefficients are polynomials in this parameter. Substituting tt with 00 yields the Schur polynomials.

Note

The name "t-Schur polynomial" is taken from Wheeler and Zinn-Justin's paper Hall polynomials, inverse Kostka polynomials and puzzles.


Skew t-Schur polynomial

Description

Returns the skew t-Schur polynomial associated to the given skew partition.

Usage

tSkewSchurPol(n, lambda, mu)

Arguments

n

number of variables, a positive integer

lambda, mu

integer partitions defining the skew partition: lambda is the outer partition and mu is the inner partition (so mu must be a subpartition of lambda)

Value

A symbolicQspray multivariate polynomial, the skew t-Schur polynomial associated to the skew partition defined by lambda and mu. It has a single parameter usually denoted by tt and its coefficients are polynomials in this parameter. Substituting tt with 00 yields the skew Schur polynomials.


Evaluation of zonal polynomial - C++ implementation

Description

Evaluates a zonal polynomial. The zonal polynomials are the Jack CC-polynomials with Jack parameter α=Z\alpha=Z.

Usage

Zonal(x, lambda)

Arguments

x

values of the variables, a vector of bigq numbers, or a vector that can be coerced as such (e.g. c("2", "5/3"))

lambda

an integer partition, given as a vector of decreasing integers

Value

A bigq number.

Examples

Zonal(c("1", "3/2", "-2/3"), lambda = c(3, 1))

Zonal polynomial - C++ implementation

Description

Returns a zonal polynomial. The zonal polynomials are the Jack CC-polynomials with Jack parameter α=Z\alpha=Z.

Usage

ZonalPol(n, lambda)

Arguments

n

number of variables, a positive integer

lambda

an integer partition, given as a vector of decreasing integers

Value

A qspray multivariate polynomial.

Examples

( zonal <- ZonalPol(3, lambda = c(3, 1)) )
zonal == JackPol(3, lambda = c(3, 1), alpha = "2", which = "C")

Zonal polynomial

Description

Returns the zonal polynomial.

Usage

ZonalPolR(n, lambda, algorithm = "DK", basis = "canonical", exact = TRUE)

Arguments

n

number of variables, a positive integer

lambda

an integer partition, given as a vector of decreasing integers

algorithm

the algorithm used, either "DK" or "naive"

basis

the polynomial basis for algorithm = "naive", either "canonical" or "MSF" (monomial symmetric functions); for algorithm = "DK" the canonical basis is always used and this parameter is ignored

exact

logical, whether to get rational coefficients

Value

A mvp multivariate polynomial (see mvp-package), or a qspray multivariate polynomial if exact = TRUE and algorithm = "DK", or a character string if basis = "MSF".

Examples

ZonalPolR(3, lambda = c(3,1), algorithm = "naive")
ZonalPolR(3, lambda = c(3,1), algorithm = "DK")
ZonalPolR(3, lambda = c(3,1), algorithm = "DK", exact = FALSE)
ZonalPolR(3, lambda = c(3,1), algorithm = "naive", basis = "MSF")

Evaluation of zonal quaternionic polynomial - C++ implementation

Description

Evaluates a zonal quaternionic polynomial. The quaternionic zonal polynomials are the Jack CC-polynomials with Jack parameter α=1/Z\alpha=1/Z.

Usage

ZonalQ(x, lambda)

Arguments

x

values of the variables, a vector of bigq numbers, or a vector that can be coerced as such (e.g. c("2", "5/3"))

lambda

an integer partition, given as a vector of decreasing integers

Value

A bigq number.

Examples

ZonalQ(c("1", "3/2", "-2/3"), lambda = c(3, 1))

Quaternionic zonal polynomial - C++ implementation

Description

Returns a quaternionic zonal polynomial. The quaternionic zonal polynomials are the Jack CC-polynomials with Jack parameter α=1/Z\alpha=1/Z.

Usage

ZonalQPol(n, lambda)

Arguments

n

number of variables, a positive integer

lambda

an integer partition, given as a vector of decreasing integers

Value

A qspray multivariate polynomial.

Examples

( zonalQ <- ZonalQPol(3, lambda = c(3, 1)) )
zonalQ == JackPol(3, lambda = c(3, 1), alpha = "1/2", which = "C")

Quaternionic zonal polynomial

Description

Returns the quaternionic (or symplectic) zonal polynomial.

Usage

ZonalQPolR(n, lambda, algorithm = "DK", basis = "canonical", exact = TRUE)

Arguments

n

number of variables, a positive integer

lambda

an integer partition, given as a vector of decreasing integers

algorithm

the algorithm used, either "DK" or "naive"

basis

the polynomial basis for algorithm = "naive", either "canonical" or "MSF" (monomial symmetric functions); for algorithm = "DK" the canonical basis is always used and this parameter is ignored

exact

logical, whether to get rational coefficients

Value

A mvp multivariate polynomial (see mvp-package), or a qspray multivariate polynomial if exact = TRUE and algorithm = "DK", or a character string if basis = "MSF".

Examples

ZonalQPolR(3, lambda = c(3,1), algorithm = "naive")
ZonalQPolR(3, lambda = c(3,1), algorithm = "DK")
ZonalQPolR(3, lambda = c(3,1), algorithm = "DK", exact = FALSE)
ZonalQPolR(3, lambda = c(3,1), algorithm = "naive", basis = "MSF")

Evaluation of quaternionic zonal polynomials

Description

Evaluates a quaternionic (or symplectic) zonal polynomial.

Usage

ZonalQR(x, lambda, algorithm = "DK")

Arguments

x

numeric or complex vector or bigq vector

lambda

an integer partition, given as a vector of decreasing integers

algorithm

the algorithm used, either "DK" (Demmel-Koev) or "naive"

Value

A numeric or complex scalar or a bigq rational number.

References

F. Li, Y. Xue. Zonal polynomials and hypergeometric functions of quaternion matrix argument. Comm. Statist. Theory Methods, 38 (8), 1184-1206, 2009

See Also

ZonalQPolR

Examples

lambda <- c(2,2)
ZonalQR(c(3,1), lambda)
ZonalQR(c(gmp::as.bigq(3),gmp::as.bigq(1)), lambda)
##
x <- c(3,1)
ZonalQR(x, c(1,1)) + ZonalQR(x, 2) # sum(x)^2
ZonalQR(x, 3) + ZonalQR(x, c(2,1)) + ZonalQR(x, c(1,1,1)) # sum(x)^3

Evaluation of zonal polynomials

Description

Evaluates a zonal polynomial.

Usage

ZonalR(x, lambda, algorithm = "DK")

Arguments

x

numeric or complex vector or bigq vector

lambda

an integer partition, given as a vector of decreasing integers

algorithm

the algorithm used, either "DK" (Demmel-Koev) or "naive"

Value

A numeric or complex scalar or a bigq rational number.

References

  • Robb Muirhead. Aspects of multivariate statistical theory. Wiley series in probability and mathematical statistics. Probability and mathematical statistics. John Wiley & Sons, New York, 1982.

  • Akimichi Takemura. Zonal Polynomials, volume 4 of Institute of Mathematical Statistics Lecture Notes – Monograph Series. Institute of Mathematical Statistics, Hayward, CA, 1984.

  • Lin Jiu & Christoph Koutschan. Calculation and Properties of Zonal Polynomials. http://koutschan.de/data/zonal/

See Also

ZonalPolR

Examples

lambda <- c(2,2)
ZonalR(c(1,1), lambda)
ZonalR(c(gmp::as.bigq(1),gmp::as.bigq(1)), lambda)
##
x <- c(3,1)
ZonalR(x, c(1,1)) + ZonalR(x, 2) # sum(x)^2
ZonalR(x, 3) + ZonalR(x, c(2,1)) + ZonalR(x, c(1,1,1)) # sum(x)^3