[FEATURE-REQUEST]

[AxionMax]

Hi Vaex team,

I'm using Vaex version 4.17.0, and I've been performing groupby operations to aggregate data. For example, I can easily compute minimum, maximum, and mean values using vaex.agg:

import vaex

df_grouped = df.groupby(by=["Inclination", "Loaded"], agg={
    'Vel_min': vaex.agg.min('Vel'),
    'Vel_max': vaex.agg.max('Vel'),
    'Vel_mean': vaex.agg.mean('Vel')
})

However, I am interested in calculating custom statistics, such as percentiles or other metrics that are not directly available through vaex.agg.

Question:

Is it possible to perform calculations like the percentile "p" or other custom statistics that are not directly implemented in vaex.agg within a groupby operation in Vaex? If not, what are the recommended approaches or workarounds for achieving this?

Thank you for your time and for developing this powerful tool!