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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 filter(self, index):
 #@ReservedAssignment """ Filters a datamat by different aspects. This function is a device to filter the datamat by certain logical conditions. It takes as input a logical array (contains only True or False for every datapoint) and kicks out all datapoints for which the array says False. The logical array can conveniently be created with numpy:: np.array([2,9]) np.array([9]) Parameters: index : array Array-like that contains True for every element that passes the filter; else contains False Returns: datamat : Datamat Instance """

        return Datamat(categories=self._categories, datamat=self, index=index)