'some basic plots'

def plot(self, y, plt=plt):

    plt.figure()
    plt.plot(self.x, self.y, 'bo-', self.x, self.yest, 'r.-')
    plt.title('sample    (training)    points')
    plt.figure()
    plt.plot(self.xpredict, y, 'bo-', self.xpredict, self.ypredict, 'r.-')
    plt.title('all    points')
