numpy.polynomial.legendre.legcompanion — NumPy v1.13 Manual (original) (raw)

numpy.polynomial.legendre. legcompanion(c)[source]

Return the scaled companion matrix of c.

The basis polynomials are scaled so that the companion matrix is symmetric when c is an Legendre basis polynomial. This provides better eigenvalue estimates than the unscaled case and for basis polynomials the eigenvalues are guaranteed to be real ifnumpy.linalg.eigvalsh is used to obtain them.

Parameters: c : array_like 1-D array of Legendre series coefficients ordered from low to high degree.
Returns: mat : ndarray Scaled companion matrix of dimensions (deg, deg).

Notes