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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 plot(self):
 """ Plot posterior from simple nonstochetric regression. """

        figure()
        plot_envelope(self.M, self.C, self.xplot)
        for i in range(3):
            f = Realization(self.M, self.C)
            plot(self.xplot,f(self.xplot))

        plot(self.abundance, self.frye, 'k.', markersize=4)
        xlabel('Female abundance')
        ylabel('Frye density')
        title(self.name)
        axis('tight')