Database.to_chenery_moses(inplace: bool = True, scenarios: list = None)

Transform an Isard SUT into a Chenery-Moses SUT.

Parameters:

• inplace – When True, mutate the current database. When False, return a transformed copy.

• scenarios – Optional subset of scenarios to transform. When omitted, the transformation applies to all available scenarios.

Returns:

Transformed database when inplace=False, otherwise None.

Return type:

Database | None

Notes

Uses native SUT flow blocks without constructing a unified Z or dense diagonal matrices. Sparse inputs retain sparse storage; common dense tables retain dense output blocks and their existing API.

Activities keep their original regional memberships. Commodity labels are matched by their exact strings. A destination market is added only where an observed nonzero use or final-demand flow requires a commodity absent from that destination’s original classification. Existing commodity nodes, including unused nodes, are retained. Commodity axes consequently describe destination markets after the transformation.

Ya, activity-side accounts and direct final-demand accounts are preserved. S, Ec and Vc are allocated with each origin commodity’s observed destination shares. Their row totals are preserved. An unused commodity retains its original supply and accounts; zero net use with nonzero regional trade flows raises WrongInput because the sourcing shares are undefined. No balancing is performed.

New commodity markets are shared by all scenarios. Unselected scenarios are extended with zeros on those axes while their existing flows are preserved. Derived caches on affected scenarios are discarded.