Digital Drosophila Archive
69 lines
4.1 KiB
Markdown
69 lines
4.1 KiB
Markdown
# Phase 4AE — GPU author-semantics numerical gate
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User authorized an independent model branch. This is not conditioning and does
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not replace any Phase 1–4AD candidate/artifact. Learning remains unachieved.
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The fixed author equations and all physical parameters come from the validated
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4AD oracle, with dt=.1ms, delay=18 steps, refractory=22 steps and W=.275mV.
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Canonical CSR, raw contact counts and frozen transmitter signs are read-only.
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## Predeclared tests
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Five synthetic numerical fixtures: ordered cancellation (including deliberately
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nonphysiological large signed integers), 256-source fan-in bursts, refractory
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release/self-loop collisions, representable threshold neighbours, and a fixed
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seed signed random graph. Synthetic negative node labels are NOT MaleCNS IDs;
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duplicate/zero edges occur only in labelled numerical fixtures.
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Two 128-neuron real induced graphs are selected before simulation: the highest
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in-degree target and its 127 largest-contact presynaptic partners; separately the
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highest-in-degree target with >=64 positive and >=63 negative presynaptic inputs,
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64 positive and 63 negative largest-contact partners. Ties break by canonical
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neuron_idx. Include every existing edge within the selected node set, without
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changing raw counts/signs or adding edges. This is numerical stress, not an input
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interface or a physiological validation. Preserve identities and selection audit.
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Also run the same five 4AD motifs for 100ms with one common seed request (or no
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request for no_input). Report every outcome; do not select by activity/separability.
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These tests do not exhaust all full-brain numerical corner cases.
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## Exact arithmetic and schedule
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Execute unchanged pinned author create_model in Brian2 2.5.1/NumPy1.22.3 using
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the isolated 4AD environment. Export raw SI variables, actual coefficients and
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weights. GPU float32 coefficients round to float32 before each multiply/add;
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float64 uses double. No FMA or fast-math. Match generated expression order.
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Update refractory and integrate; apply only currently permitted voltage seed
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requests; strict threshold closes write access immediately; then accept delayed
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anatomical arrivals in author order within each target, external synthetic input,
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and reset. A fused reset is equivalent only if all arrivals reject current spikes.
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Never replace sequential g+=w with g+sum(w). A queue proxy observes real Brian
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arrival order without changing values; compare proxy and unwrapped runs exactly.
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Use an exact spike ring buffer, no approximated delay or dense edge scan.
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Before-threshold requests use the existing common requested-event convention,
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not the author's distinct poi interface that changes target refractory to zero.
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Report requested/accepted/rejected input separately. No graded APL in these isolated
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tests; its future integration and frozen coefficients require explicit audit.
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For each case/precision compare GPU to the same-precision real Brian oracle:
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exact events, counts, refractory, input delivery and per-target arrival order/guard;
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report full-history max/mean V/g error and bitwise state comparison. Fixed tolerance
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is 1e-11V float64 / 1e-6V float32. Any event divergence fails, regardless of tolerance.
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Each GPU case repeats three times with all arrays exactly equal. Cross-precision
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differences are separately descriptive, not grounds to change thresholds.
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## Integrity and progression
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Preregister sources, old input hashes and deterministic fixture hashes before any
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model execution. Preserve failures; use a separately recorded new attempt for
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implementation repairs. Do not change frozen artifacts. Save manifests/SHA-256.
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Old five deterministic-v2 full-brain reference regressions must pass again.
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Only then consider a short full-graph author comparison, followed by DoOR CAL;
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never claim full-brain equivalence or learning from isolated test PASS.
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Author source/license/provenance are inherited read-only from 4AD. Supporting
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primary documentation: https://numpy.org/doc/1.22/reference/generated/numpy.ufunc.at.html
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and https://brian2.readthedocs.io/en/2.5.1/user/refractoriness.html . The fixed
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generated source and actual boundary fixtures, not simplified prose, define timing.
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