nabla {tfarima}

Unscramble I polynomial

Description

nabla multiplies the I polynomials of an object of the um class.

Usage

nabla(um)

## S3 method for class 'um'
nabla(um)

Arguments

um

an object of class um.

Value

A numeric vector c(1, a1, ..., ad)

Note

This function returns the member variable um$nabla.

Examples

um1 <- um(i = "(1 - B)(1 - B^12)")
nabla(um1)