Initialises the clusters by distributing the items from the data.
        evenly across n clusters

        :param input_: the data set (a list of tuples).
        :param clustercount: the amount of clusters (n).

def initialise_clusters(self, input_, clustercount):
        """
        Initialises the clusters by distributing the items from the data.
        evenly across n clusters

        :param input_: the data set (a list of tuples).
        :param clustercount: the amount of clusters (n).
        """
        # initialise the clusters with empty lists
        self.__clusters = []
        for _ in range(clustercount):
            self.__clusters.append([])

        # distribute the items into the clusters
        count = 0
        for item in input_:
            self.__clusters[count % clustercount].append(item)
            count += 1