def transform(func, data):
    """Apply <func> on each element in <data> and return the list
consisting of the return values from <func>.

>>> data = [[10,20], [30,40], [50,60]]
... chart_data.transform(lambda x: [x[0], x[1]+1], data)
[[10, 21], [30, 41], [50, 61]]

"""
    out = []
    for r in data:
        out.append(func(r))
    return out