minus

Lag operator polynomial subtraction

Syntax

C = minus(A, B, 'Tolerance', tolerance)
C = A -B


Description

Given two lag operator polynomials A(L) and B(L), C = minus(A, B, 'Tolerance', tolerance) performs a polynomial subtraction C(L) = A(L) – B(L) with tolerance tolerance. 'Tolerance' is the nonnegative scalar tolerance used to determine which coefficients are included in the result. The default tolerance is 1e–12. Specifying a tolerance greater than 0 allows the user to exclude polynomial lags with near-zero coefficients. A coefficient matrix of a given lag is excluded only if the magnitudes of all elements of the matrix are less than or equal to the specified tolerance.

C = A -B performs a polynomial subtraction.

If at least one of A or B is a lag operator polynomial object, the other can be a cell array of matrices (initial lag operator coefficients), or a single matrix (zero-degree lag operator).

Examples

Subtract Two Lag Operator Polynomials

Create two LagOp polynomials and subtract one from the other:

A = LagOp({1 -0.6 0.08});
B = LagOp({1 -0.5});
A-B

ans = 
    1-D Lag Operator Polynomial:
    -----------------------------
        Coefficients: [-0.1 0.08]
                Lags: [1 2]
              Degree: 2
           Dimension: 1

Algorithms

The subtraction operator (–) invokes minus, but the optional coefficient tolerance is available only by calling minus directly.