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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def vertical_modes(self):
 """ Calculate standard vertical modes. Simply the eigenvectors of the stretching matrix S """


        evals,evecs = np.linalg.eig(-self.S)

        asort = evals.argsort()

        # deformation wavenumbers and radii
        self.kdi2 = evals[asort]
        self.radii = np.zeros_like(self.kdi2)
        self.radii[0] = self.g*self.H/np.abs(self.f) # barotropic def. radius
        self.radii[1:] = 1./np.sqrt(self.kdi2[1:])

        # eigenstructure
        self.pmodes = evecs[:,asort]

        # normalize to have unit L2-norm
        Ai = (self.H / (self.Hi[:,np.newaxis]*(self.pmodes**2)).sum(axis=0))**0.5
        self.pmodes = Ai[np.newaxis,:]*self.pmodes