jquery: Group by Timegrouper group "backwards"

samedi 2 juillet 2016

I have this time-series:

rng = pd.date_range('2016-06-01', periods=24*7, freq='H')
ones = pd.Series([1]*24*7, rng)
rdf = pd.DataFrame({'a': ones})

Last entry is 2016-06-07 23:00:00. I now want to group this by, say two days, basically like so:

rdf.groupby(pd.TimeGrouper('2D')).sum()

However, I want to group starting from my last data point backwards, so instead of getting this result:

            a
2016-06-01  48
2016-06-03  48
2016-06-05  48
2016-06-07  24

I'd much rather expect this:

            a
2016-06-01  24
2016-06-03  48
2016-06-05  48
2016-06-07  48

and when grouping by '3D':

            a
2016-06-01  24
2016-06-04  72
2016-06-07  72

Expected outcome when grouping by '4D' is:

            a
2016-06-03  72
2016-06-07  96

I am not able to get this with every combination of closed, label etc. I could think of.

How can I achieve this?

jquery