Primitive part of a polynomial
MuPAD® notebooks will be removed in a future release. Use MATLAB® live scripts instead.
MATLAB live scripts support most MuPAD functionality, though there are some differences. For more information, see Convert MuPAD Notebooks to MATLAB Live Scripts.
polylib::primpart(f) returns the primitive
part of the polynomial
If the first argument is an expression, it is converted into
a polynomial in the indeterminates specified by the second argument,
or in all of its indeterminates if no second argument is given.
the expression cannot be converted into a polynomial.
For a rational number, its sign is returned.
In the following example, a bivariate polynomial is given. Its coefficients are the integers 3, 6, and 9; the primitive part is obtained by dividing the polynomial by their gcd.
polylib::primpart(poly(6*x^3*y + 3*x*y + 9*y, [x, y]));
However, consider the same polynomial viewed as a univariate
x. Its coefficients are polynomials
y in this case, and their gcd
polylib::primpart(poly(6*x^3*y + 3*x*y + 9*y, [x]));
polylib::primpart divides the coefficients
by their gcd, but does not normalize the result. This must be done
polylib::primpart(4*x*y + 6*x^3 + 6*x*y^2 + 9*x^3*y, [x])
normal(polylib::primpart(4*x*y + 6*x^3 + 6*x*y^2 + 9*x^3*y, [x]))
List of identifiers
polylib::primpart returns an object of the
same type as the input, or
The primitive part of a polynomial f is a polynomial g whose coefficients are relatively prime such that f = rg for some element r of the coefficient ring.