spray (version 1.0-6)

zero: The zero polynomial

Description

Test for the zero, or empty, polynomial

Usage

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

Arguments

L

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

d

Integer specifying dimensionality of the spray (the arity)

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

# NOT RUN {
a <- lone(1,3)

is.zero(a-a)  # should be TRUE

is.zero(zero(6))

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

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





# }