flopscope.accounting.eigvalsh_cost
flopscope.accounting.eigvalsh_cost(n)[flopscope source]
Weighted FLOP cost of computing eigenvalues of a symmetric matrix.
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.
4n^3/3: tridiagonalization, values only (G&VL 4e §8.3). 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.