numpoly.roots¶
- numpoly.roots(poly: numpoly.typing.PolyLike) → numpy.ndarray[source]¶
Return the roots of a polynomial.
Assumes the polynomial has a single dimension.
- Args:
- poly:
Polynomial to take roots of, or if constant, the coefficients of said polynomial. This to be compatible with
numpy.roots()
.
- Return:
An array containing the roots of the polynomial.
- Raise:
- ValueError:
When poly cannot be converted to a rank-1 polynomial.
- Note:
The algorithm relies on computing the eigenvalues of the companion matrix 1.
- 1
R. A. Horn & C. R. Johnson, Matrix Analysis. Cambridge, UK: Cambridge University Press, 1999, pp. 146-7.
- Example:
>>> q0 = numpoly.variable() >>> poly = 3.2*q0**2+2*q0+1 >>> numpoly.roots(poly) array([-0.3125+0.46351241j, -0.3125-0.46351241j]) >>> numpoly.roots([3.2, 2, 1]) array([-0.3125+0.46351241j, -0.3125-0.46351241j])