numpy.roots
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numpy.roots(p)
[source] -
Return the roots of a polynomial with coefficients given in p.
The values in the rank-1 array
p
are coefficients of a polynomial. If the length ofp
is n+1 then the polynomial is described by:p[0] * x**n + p[1] * x**(n-1) + ... + p[n-1]*x + p[n]
Parameters: -
p : array_like
-
Rank-1 array of polynomial coefficients.
Returns: -
out : ndarray
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An array containing the roots of the polynomial.
Raises: - ValueError
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When
p
cannot be converted to a rank-1 array.
See also
Notes
The algorithm relies on computing the eigenvalues of the companion matrix [1].
References
[1] R. A. Horn & C. R. Johnson, Matrix Analysis. Cambridge, UK: Cambridge University Press, 1999, pp. 146-7. Examples
>>> coeff = [3.2, 2, 1] >>> np.roots(coeff) array([-0.3125+0.46351241j, -0.3125-0.46351241j])
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https://docs.scipy.org/doc/numpy-1.17.0/reference/generated/numpy.roots.html