P_DEG Function

Numerically determines the degree of a polynomial.

Usage

result = P_DEG(a)

Input Parameters

a—An array of coefficients of a polynomial.

Returned Value

result—The degree of the polynomial.

Keywords

Epsilon—Specifies a value above which P_DEG ignores higher order coefficients of the polynomial. If Epsilon is not set, the default value is based on the square root of machine epsilon.

Discussion

For a given polynomial A(z), such as:

A(z) = a₀ + a₁z^–1 + a₂z^–2 + ... + a_Nz^–N

P_DEG determines M £ N such that a_i £ Epsilon for i = M + 1, M + 2, ..., N.

Example

In this example, the degree of a polynomial A(z) = 5 + 4z^–1 + 8z^–2 + z^–3 is computed with trailing zeros.

a= [5, 4, 8, 1, 0, 0, 0, 0]

PRINT, P_DEG(a)