def mean_clone_size(clone_size_dist):
    # Mean of surviving clones from a clone size frequency array
    """Gets the mean of clones > 1 cell. For dists that start at 0 cell clones"""
    return sum([(i) * clone_size_dist[i] for i in range(1, len(clone_size_dist))]) / clone_size_dist[1:].sum()