Reset bias clamped to non-negative in PulsedRPUDeviceMetaParameter::initialize may block valid negative decay point #755
Description
Description
In src/rpucuda/rpu_pulsed_device.h:113, reset is clamped to non‑negative (reset = MAX(reset, (T)0.0);). This prevents negative reset bias values. However, reset is used as the decay convergence point (w = (w - b) * s + b), and negative convergence points are valid when bounds are symmetric or negative. The clamp changes the intended behavior and contradicts the docs for PulsedDevice (no sign restriction).
How to reproduce
Run decay or update steps with devices having negative reset point. (e.g. reset = -0.5)
Expected behavior
Weights should decay to -0.5 but do decay to 0.0.
- Pytorch version: 2.4.1
- Package version: 1.0.0
- OS: Ubuntu 22.04.4 LTS (WSL2 kernel: Linux-6.6.87.2-microsoft-standard-WSL2-x86_64)
- Python version: 3.12.5 (CPython)
- Conda version (or N/A): 24.11.3