# 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

expand all

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.