spray (version 1.0)

zero:

Description

Test for the zero, or empty, polynomial

Usage

is.zero(L)
is.empty(L)

Arguments

L

A two-element list of indices and values, possibly a spray object

Details

Functions is.empty() and is.zero() are synonyms. If spray objects are interpreted as multivariate polynomials, “is.zero()” is more intuitive, if sprays are interpreted as sparse arrays, “is.empty()” is better (for me).

Examples

is.zero(zero)  # should be TRUE


x <- spray(t(0:1))
y <- spray(t(1:0))

is.zero((x+y)*(x-y)-(x^2-y^2)) # TRUE