flopscope.

flopscope.accounting.eig_cost

flopscope.accounting.eig_cost(n)[flopscope source]

Weighted FLOP cost of eigendecomposition.

Parameters

n:int

Number of columns in the input matrix.

Returns

:int

Weighted public cost estimate, floored to match runtime accounting.

Notes

This helper multiplies the analytical FLOP count by the active weight from flopscope._weights and then applies int(...) so public estimates match budget deductions.

Hessenberg reduction + Francis QR with eigenvector backtransform (LAPACK Users' Guide Table 3.13 DGEEV / G&VL 4e §7.5). Confirmed by the 2026-06 evidence audit (LAPACK Users' Guide Table 3.13 / G&VL 4e §7.5, §8.3 + runtime scaling); see docs/reference/cost-model.md.