30 lines
1.3 KiB
Python
30 lines
1.3 KiB
Python
"""
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07_dps_level3_single.py
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A single DPS level-3 feasibility check on the pure Tiles state, to confirm
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the construction works and see its cost before committing to a full
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noise-threshold bisection (see 08_dps_level_k_bisection.py).
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In the original sandbox this took ~137s with SCS (single solve, cold
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start). Expect similar or better on a modern laptop; likely far faster
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with an interior-point solver (MOSEK, if you have a license) since the
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PSD cone here (81x81 complex Hermitian) is small by modern SDP standards
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-- SCS is a first-order method tuned for large sparse problems and is not
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especially fast on small/dense feasibility problems like this one.
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Expected result: status "infeasible" (i.e. entanglement IS detected).
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"""
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import time
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import cvxpy as cp
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from common import RHO_TILES
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from dps_hierarchy import build_dps_problem, dps_feasible
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SOLVER = cp.SCS # try cp.MOSEK if available -- likely much faster at this size
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prob, rho_param, sigma = build_dps_problem(d=3, k=3)
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print(f"sigma shape: {sigma.shape} "
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f"PPT-constraint (PSD cone) size: {3 * 3 ** 3} x {3 * 3 ** 3}")
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t0 = time.time()
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ok = dps_feasible(prob, rho_param, RHO_TILES, solver=SOLVER, eps=1e-6, max_iters=20000)
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print(f"DPS level-3 feasible: {ok} status={prob.status} [{time.time() - t0:.1f}s]")
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