polsub

Polynomial Subtraction

SYNOPSIS:

int maxpol, na, nb, nc;
double a[], b[], c[];

nc = max(na, nb);
polini( nc );
polsub( a, na, b, nb, c );

DESCRIPTION:

polsub( a, na, b, nb, c ); c = b - a, nc = max(na, nb)

a, b, c are polynomials of degree na, nb, nc respectively.
The degree of a polynomial cannot exceed a run-time value MAXPOL.
An operation that attempts to use or generate a polynomial of higher degree might produce a result that suffers truncation at degree MAXPOL.
The value of MAXPOL is set by calling the function
polini( MAXPOL );

Each polynomial is represented by an array containing its coefficients, together with a separately declared integer equal to the degree of the polynomial.
The coefficients appear in ascending order; that is:

2 na
a(x) = a[0] + a[1] * x + a[2] * x + ... + a[na] * x .