isPolynomialOf function

Whether a 'qspray' is a polynomial of some given 'qsprays'

Checks whether a qspray polynomial can be written as a polynomial of some given qspray polynomials. If TRUE, this polynomial is returned.

isPolynomialOf(qspray, qsprays)

Arguments

• qspray: a qspray object
• qsprays: a list of qspray objects

Returns

A Boolean value indicating whether the polynomial defined by qspray can be written as a polynomial of the polynomials defined by the qspray objects given in the qsprays list. If this is TRUE, this polynomial is returned as an attribute named "polynomial".

Examples

library(qspray)
x <- qlone(1); y <- qlone(2); z <- qlone(3)
q1 <- x + y
q2 <- x*z^2 + 4
qspray <- q1^2*q2 + 2*q1 + 3
( check <- isPolynomialOf(qspray, list(q1, q2)) )
POLYNOMIAL <- attr(check, "polynomial")
changeVariables(POLYNOMIAL, list(q1, q2)) == qspray # should be TRUE