def _draw_heatmap(*args, **kwargs):
    """Wraps seaborn.heatmap to work with long, tidy format dataframes.
    """
    import seaborn as sb
    data = kwargs.pop('data')
    d = data.pivot(index=args[1], columns=args[0], values=args[2])
    return sb.heatmap(d, **kwargs)
