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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 ind_zero_freq(self):
 """ Index of the first point for which the freqencies are equal or greater than zero. """

        ind = np.searchsorted(self.frequencies, 0)
        if ind >= len(self.frequencies):
            raise ValueError("No positive frequencies found")
        return ind