# Rain EP Released-Drift Profile

## Scope

This protocol asks whether a local affine predictor adds value beyond a local
intercept when hardware update bias changes with the adaptive parameter state.
It is a controlled neural-network transfer of a shape measured in released
physical traces. It is not a reproduction of the resistor hardware and is not
labeled as a real-hardware neural-network result.

The source is the committed analysis
`results/physical_bias/p0_state_dependence.json`, derived from Zenodo record
15692914, release v1.0.1. For each of four measured edges, the report supplies
an affine offset, local gate-voltage slope, and the gate range visited in the
retained drift traces. The transfer profile divides both the offset and the
slope times observed gate range by the RMS of the four offsets. This freezes
the following dimensionless values without a task-accuracy fit:

- offsets: `0.93562, 1.60206, -0.10014, 0.74026`;
- full-range state variations: `0.52595, 0.31317, 0.38320, -0.04782`.

Neural parameters are deterministically assigned these four profiles. Their
initial local update-offset RMS is set by `bias_ratio`; parameter displacement
in units of that tensor's initial parameter RMS maps through `tanh` to the
measured state-range coordinate. This mapping preserves the measured relative
state dependence but does not claim that resistor gate volts equal neural
weight units.

## Local observation contract

At a neutral probe, the teaching input to the local update circuit is disabled.
The corrector receives the resulting measured circuit output at its current
parameter state. It is not given an externally calibrated coefficient. An
intercept-only predictor and affine SDIL receive identical probes. All
parameters probe in parallel, so probe count is independent of parameter count;
each parameter stores its own predictor coefficients.

## R0 development screen

R0 begins only after `dillavou_c0` finishes. It uses the same 10,000/2,000
training-only split as development, batch size 128, one epoch, fixed bias ratio
1.0, and the released affine profile. Eight cells run:

1. clean positive EP;
2. raw released-profile bias;
3. intercept-only, one initial probe;
4. affine SDIL, one initial probe;
5. intercept-only, one initial probe then every 10 steps;
6. affine SDIL with the same probes;
7. intercept-only, one initial probe then every 50 steps;
8. affine SDIL with the same probes.

R0 is a mechanics/development screen. A useful result requires affine SDIL to
have lower held-out residual bias and higher task accuracy than the matched
intercept-only arm. Final evidence additionally requires multiple seeds, a
frozen probe cadence, measurement noise/quantization, and the strong-clamp
baseline.