deed936ca0bfa5998af0225fab99c47bd2bc4b6d,mathics/builtin/linalg.py,Eigenvalues,apply,#Eigenvalues#Any#Any#,715

Before Change

        if matrix.cols != matrix.rows or matrix.cols == 0:
            return evaluation.message("Eigenvalues", "matsq", m)
        eigenvalues = matrix.eigenvals().items()
        try:
            eigenvalues = sorted(eigenvalues,
                                 key=lambda v_c: (abs(v_c[0]), -v_c[0]), 
                                 reverse=True)
        // Try to sort the results as complex numbers
        except TypeError:
            try:
                eigenvalues = sorted(eigenvalues,
                                     key=lambda v_c: -abs(v_c[0]))
            // Don"t sort the results at all
            except TypeError:
                pass

        return from_sympy([v for (v, c) in eigenvalues for _ in range(c)])


class Eigensystem(Builtin):

After Change

        eigenvalues = list(matrix.eigenvals().items())

        // Sort the eigenvalues in the Mathematica convention
        if all(v.is_complex for (v, _) in eigenvalues):
            eigenvalues.sort(key=lambda v: (abs(v[0]), - re(v[0]), - im(v[0])),
                             reverse=True)

            eigenvalues = [from_sympy(v) for (v, c) in eigenvalues 
                           for _ in range(c)]
        // Sort the eigenvalues in an arbitrary yet deterministic order
        else:
            eigenvalues = [(from_sympy(v), c) for (v, c) in eigenvalues]
            eigenvalues.sort(key=lambda v: v[0].get_sort_key())

            eigenvalues = [v for (v, c) in eigenvalues for _ in range(c)]

        return Expression("List", *eigenvalues)


class Eigensystem(Builtin):

Instances