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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 evalPDF(self, u_values):
        '''Returns the PDF of the uncertain parameter evaluated at the values
        provided in u_values.

        :param iterable u_values: values of the uncertain parameter at which to
            evaluate the PDF

        *Example Usage* ::

            >>> u = UniformParameter()
            >>> X = numpy.linspace(-1, 1, 100)
            >>> Y = [u.evalPDF(x) for x in X]

        '''

        if isinstance(u_values, np.ndarray):
            return self._evalPDF(u_values)
        else:
            try:
                iter(u_values)
                return [self._evalPDF(u) for u in u_values]
            except:
                return self._evalPDF(u_values)