Reference LSM

Reference LSM (reference_lsm.jl)

Generated with Grok Build: Grok 4.5 · xAI Imagine (/imagine)

A 2,048-neuron dense CUDA reservoir for rapid prototyping. Not exported on the public API surface (call via LiquidCortex.run_lsm_step / module-qualified internals). Prefer SparseBrain / EnsembleBrain for production capacity.

Constants

Constant	Value
REF_N	2048
REF_IN_DEFAULT	16
REF_OUT_DEFAULT	16

Lazy GPU State

Globals start as nothing / defaults so using LiquidCortex works without a GPU:

Ref	Content
_ref_W	CuMatrix{Float32} recurrent weights
_ref_Win	CuMatrix{Float32} input weights
_ref_Wout	CuMatrix{Float32} readout
_ref_x	CuVector{Float32} reservoir state
_ref_n_in / _ref_n_out	Locked dimensions after init
_ref_initialized	Boolean gate

Manual init

LiquidCortex._init_ref_lsm!(; n_in=8, n_out=4)

• Validates positive dimensions.
• Initializes W ~ N(0, 0.02), Win ~ N(0, 0.5), Wout ~ N(0, 0.1) via cpu_randn_cu.
• Zeros state vector of length REF_N.

Lazy init

First run_lsm_step without prior init:

• Errors if !_cuda_available[].
• Calls _init_ref_lsm!(; n_in=length(inputs_vec), n_out=n_out).

Step API

y = LiquidCortex.run_lsm_step(inputs_vec::Vector{Float32}, inhibit_val::Float32; n_out=16)
# y :: Vector{Float32} on CPU

Dynamics:

u = cu(inputs_vec)
gain = 1 − 0.4 * inhibit_val
x ← tanh(gain * (W x + Win u))
y = Array(Wout * x)

Throws DimensionMismatch if length(inputs_vec) ≠ _ref_n_in after init.

String helper

s = LiquidCortex.run_lsm_step_str(inputs_vec, inhibit_val; n_out=16)
# comma-separated floats for IPC / shell integration

Vs SparseBrain

Aspect	Reference LSM	SparseBrain
Size	2,048 dense	65,536 sparse
Activation	Continuous tanh state	LIF spikes + OU noise
Inhibition	Recurrent gain shrink	Dynamic threshold raise
Plasticity	None online	STDP traces + W_out Hebb
State model	Module-level singleton	Instance structs
Export	Internal helpers	Public API

Testing Notes

test/runtests.jl (main) includes GPU tests that:

• Snapshot / clear / restore reference globals to avoid cross-test pollution.
• Cover lazy init, custom dims, ArgumentError / DimensionMismatch, and string output.

See Test Suite.

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Last updated: July 28, 2026 Updated by: Grok Build: Grok 4.5 Package tip reference: 4e2698c (main)