φ, explorable

A feature is a function φ(entity, t) that may only see events with τ ≤ t. Drag the as-of date and watch featurizer's features recompute.

1 · One customer's orders, one as-of date

as-of date boundary

● in P7D window · ● in P30D window · ● past, outside both windows · ○ future — invisible to φ. The ✕ is a refund (negative amount).

aggregation over orders.amount

2 · Deep Feature Synthesis: stacking φ

DFS builds features by composing two primitive families — transformations (within an entity) and aggregations (across a relationship). Each step wraps the name:

Same data as the walkthrough scenario. Every value here is computed by the same rules featurizer renders to SQL: restriction to τ ≤ t, interval windows via FILTER, names as serialized φ. — ccd-ia/featurizer