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Semantic Aggregation (Custom & Hierarchical)

Structural paths are often too granular to communicate directly. fastspa supports post-processing aggregation of results into semantic groups.

Custom sector grouping​

Aggregate by leaf (emission source sector) into user-defined groups:

paths = spa.analyze(sector=42, depth=8)

mapping = {
    0: "Primary",
    1: "Secondary",
    2: "Services",
}

by_group = paths.semantic_aggregate(mapping)

If sector names were provided, mappings can also be name-based:

mapping = {
    "Agriculture": "Primary",
    "Manufacturing": "Secondary",
    "Services": "Services",
}
by_group = paths.semantic_aggregate(mapping)

Hierarchical aggregation​

Provide multiple mappings to build multi-level group keys:

level_1 = {0: "Goods", 1: "Goods", 2: "Services"}
level_2 = {0: "Agriculture", 1: "Manufacturing", 2: "Services"}

hier = paths.hierarchical_aggregate([level_1, level_2])
# keys look like: ("Goods", "Manufacturing")

Notes​

  • Aggregation is a post-processing step: it does not change SPA traversal.
  • By default, aggregation uses the leaf sector; you can also aggregate by other stages.