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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 jbcorrelation(sites_or_distances, imt, vs30_clustering=False):
 """ Returns the Jayaram-Baker correlation model. :param sites_or_distances: SiteCollection instance o ristance matrix :param imt: Intensity Measure Type (PGA or SA) :param vs30_clustering: flag, defalt false """

        if hasattr(sites_or_distances, 'mesh'):
            distances = sites_or_distances.mesh.get_distance_matrix()
        else:
            distances = sites_or_distances

        # formulae are from page 1700
        if imt.period < 1:
            if not vs30_clustering:
                # case 1, eq. (17)
                b = 8.5 + 17.2 * imt.period
            else:
                # case 2, eq. (18)
                b = 40.7 - 15.0 * imt.period
        else:
            # both cases, eq. (19)
            b = 22.0 + 3.7 * imt.period

        # eq. (20)
        return numpy.exp((- 3.0 / b) * distances)