The zero operator

The zero operator maps any function to the zero function (which maps anything to zero). To test for something being zero, use spray::is.zero(); package idiom would be is.zero().

Function zero() takes a single argument which is interpreted as the dimension of the result. So zero(dim(a)) returns a*0 (but is faster).

Usage

zero(d)

Arguments

d

Integer specifying dimensionality of the weyl object (twice the spray arity)

Value

A weyl object corresponding to the zero operator (or a Boolean for is.zero())

Examples

(a <- rweyl(d=5))
#> A member of the Weyl algebra:
#>   1  2  3  4  5 d1 d2 d3 d4 d5     val
#>   0  1  0  0  0  1  2  2  2  1  =    3
#>   1  0  1  1  0  1  2  2  1  1  =    2
#>   1  1  2  2  1  0  0  2  0  1  =    1
is.zero(a)
#> [1] FALSE
is.zero(a-a)
#> [1] TRUE
is.zero(a*0)
#> [1] TRUE

a == a + zero(dim(a))
#> [1] TRUE

zero(8)
#> A member of the Weyl algebra:
#> empty sparse array with 16 columns