eigenvalue.py 文件源码

def verSchur(A):
    '''
    a function that verifies Schur inequality
    test whether the sum of all square eigenValue is less than or equal to Frobenius norm of the matrix
    '''
    # initialize eigenValue
    eigenValue = la.eig(A)[0]

    if np.sum(eigenValue**2) <= la.norm(A, 'fro')**2:
        return True
    else:
        return False

# approximation of the upper bound of the absolute value of each eigenValue