def _parse_seqs(self, LOS):
        """
        m._parse_seqs(LOS) -- [utility] Build a matrix of counts from a list of sequences
        """
        self.nseqs = len(LOS)
        self.width = len(LOS[0])
        for i in range(self.width):
            Dc = {'A': 0, 'C': 0, 'T': 0, 'G': 0, 'N': 0}
            for seq in LOS:
                key = seq[i]
                Dc[key] = Dc[key] + 1
            del(Dc['N'])
            self.counts.append(Dc)