[FR] Add percentile (quantile) aggregation

[tadejsv]

Proposal Summary

I would like an aggregation that could compute a percentile/quantile. These values can sometimes be more informative than just mean / standard deviation (which are available now).

What areas of FiftyOne does this feature affect?

• App: FiftyOne application
• Core: Core fiftyone Python library
• Server: FiftyOne server

Willingness to contribute

The FiftyOne Community encourages new feature contributions. Would you or
another member of your organization be willing to contribute an implementation
of this feature?

• Yes. I can contribute this feature independently.
• Yes. I would be willing to contribute this feature with guidance from
  the FiftyOne community.
• No. I cannot contribute this feature at this time.

[brimoor]

Hi @tadejsv 👋

Makes sense! I added support for this in #1937.

Note that, in the meantime, you can compute quantiles in an equivalent but less efficient way as follows:

import numpy as np
import fiftyone as fo
import fiftyone.zoo as foz

dataset = foz.load_zoo_dataset("quickstart")

values = dataset.values("uniqueness")
print(np.quantile(values, [0.25, 0.5, 0.75, 0.9], method="inverted_cdf"))

values = dataset.values("predictions.detections.confidence", unwind=True)
print(np.quantile(values, [0.25, 0.5, 0.75, 0.9], method="inverted_cdf"))

[tadejsv]

Great, thank you 🙏