Median, i.e. quantile 0.5.

Calculate quantile of a specific value.

Mean.

>>> mean (tdigest [1..100] :: TDigest 10)
Just 50.5

Note: if you only need the mean, calculate it directly.

Variance.

Standard deviation, square root of variance.

Cumulative distribution function.

Note: if this is the only thing you need, it's more efficient to count this directly.

An alias for quantile