PrincetonUniversity / PsyNeuLink / 36894258542

84%

master: 84%

Build Type

Pull #3671

github

Committed by web-flow

Commit Message

Fix correlated noise in PEC and OCM simulations (#3664)

PEC and OCM previously broadcast the same seed to every stochastic
component within an estimate. In models with multiple noisy LCAs, this
could produce identical noise sequences across components and
unintentionally change the model’s behavior.
This PR introduces noise_stream_policy, defaulting to "independent" for
both PEC and OCM:

- Assigns distinct, reproducible seeds to each component and estimate,
with bounds that prevent seed collisions or rounding in float32 and
float64 execution.
- Preserves common random numbers across parameter candidates: each
component reuses its own stream when requested.
- Preserves seed-offset transformations when control projections pass
through nested compositions.
- Provides "shared_seed" to reproduce the previous behavior.

**Compatibility**: The new default changes seeded results for models
with multiple random components. Historical DDM fitting regressions
explicitly select "shared_seed" to retain their reference trajectories.
**Validation**: Regression tests cover Python and LLVM execution, nested
compositions, Gaussian noise and LCAs, candidate replay, thread-count
reproducibility, seed-range boundaries, and legacy behavior.

Pull Request Pull Request #3671: [auto] devel -> master

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11708 of 15164 branches covered (77.21%)

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1240 of 1381 new or added lines in 44 files covered. (89.79%)

20 existing lines in 8 files now uncovered.

40011 of 46133 relevant lines covered (86.73%)

0.87 hits per line