70. CamSync — inter-cameral / cross-mesh weight blend

Part: VII · Apps
Package: github.com/openfluke/welvet/layers/parallel
Status: ok — ✅ CamSync

When

Building or training a net that needs the layers/parallel Op (also usable as a Parallel cam).

Where

import "github.com/openfluke/welvet/layers/parallel"

cd 70-cam-sync && source ../env.sh && go run .

Why

Mix BranchModes and different inits let cams diverge on purpose. Sometimes you want them to share — gently (1% pull) or hard (full average) — within a Parallel, across Stack children, or even between same-shaped stores sitting on wildly different mesh layouts (1×2×1 ↔ 2×4×5). That is CamSync: couple weights without collapsing the graph into one Dense.

What

CamSyncConfig{Alpha, When, Groups, Cross}. BlendStores pulls every store in a clique toward the mean. Empty Groups = all cams; Cross wires SyncEndpoint pairs across layers/cams. Shape rule: Rows×Cols must match. Bidirectional today; one-way teacher→student not yet.

Sample output (captured)

cosine before=-0.0697 after=1.0000

Live capture from go run ./cmd/runall on local ../../welvet (exit 0).

Source

Copied from the Welvet feature book examples (openfluke.github.io/welvet/examples/70-cam-sync).

package main

import (
	"fmt"

	"github.com/openfluke/welvet/core"
	"github.com/openfluke/welvet/layers/dense"
	"github.com/openfluke/welvet/layers/parallel"
	"github.com/openfluke/welvet/quant"
	"github.com/openfluke/welvet/stub/seed"
	"github.com/openfluke/welvet/weights"
)

func main() {
	s, err := parallel.Bicameral(8, 16, 1, core.ActivationLeakyReLU,
		core.DTypeFloat32, quant.FormatNone)
	if err != nil {
		panic(err)
	}
	hemi := s.Children[1].(*parallel.Layer)
	left := hemi.Branches[0].(*dense.Layer).Weights
	right := hemi.Branches[1].(*dense.Layer).Weights
	_ = seed.InitStoreHe(left, 16, seed.From("cam0"))
	_ = seed.InitStoreHe(right, 16, seed.From("cam1"))

	hemi.SetCamSync(parallel.CamSyncConfig{
		Enabled: true,
		Alpha:   1.0,
		When:    parallel.SyncManual,
	})
	before, _ := weights.StoreCosine(left, right)
	if err := hemi.SyncNow(); err != nil {
		panic(err)
	}
	after, _ := weights.StoreCosine(left, right)
	fmt.Printf("cosine before=%.4f after=%.4f\n", before, after)
}