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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 _initialize(self):
 """Set up and normalize initial data once input data is specified."""

        self.y_transform = self.y - numpy.mean(self.y)
        self.y_transform /= numpy.std(self.y_transform)
        self.x_transforms = [numpy.zeros(len(self.y)) for _xi in self.x]
        self._compute_sorted_indices()