Distribution of projected separations

        Returns a :class:`simpledists.Hist_Distribution` object.

        :param rmax: (optional)
            Maximum radius to calculate distribution.

        :param dr: (optional)
            Bin width for histogram

        :param smooth: (optional)
            Smoothing parameter for :class:`simpledists.Hist_Distribution`

        :param nbins: (optional)
            Number of bins for histogram

        :return:
            :class:`simpledists.Hist_Distribution` describing Rsky distribution

def rsky_distribution(self,rmax=None,smooth=0.1,nbins=100):
        """
        Distribution of projected separations

        Returns a :class:`simpledists.Hist_Distribution` object.

        :param rmax: (optional)
            Maximum radius to calculate distribution.

        :param dr: (optional)
            Bin width for histogram

        :param smooth: (optional)
            Smoothing parameter for :class:`simpledists.Hist_Distribution`

        :param nbins: (optional)
            Number of bins for histogram

        :return:
            :class:`simpledists.Hist_Distribution` describing Rsky distribution

        """
        if rmax is None:
            if hasattr(self,'maxrad'):
                rmax = self.maxrad
            else:
                rmax = np.percentile(self.Rsky,99)
        dist = dists.Hist_Distribution(self.Rsky.value,bins=nbins,maxval=rmax,smooth=smooth)
        return dist