Ticket: GH-442 | Contract: merge.md §strategies
Six additional merge strategies for Arcee MergeKit parity: Task Arithmetic,
NuSLERP, MultiSLERP, DELLA, Breadcrumbs, and SCE.
| Strategy | Base Required | Models | Description |
|---|
task-arithmetic | yes | 2+ | Linear combination of task vectors |
nuslerp | no | 2 | Enhanced SLERP with nlerp fallback |
multi-slerp | no | 2+ | Barycentric SLERP for >2 models |
della | yes | 2+ | Adaptive magnitude pruning (like DARE but magnitude-aware) |
breadcrumbs | yes | 2+ | Task arithmetic + outlier removal |
sce | no | 2+ | Variance-adaptive per-tensor weighting |
use aprender::format::converter::merge::{MergeOptions, MergeStrategy};
// Task Arithmetic: base + Σ(scale_i * (model_i - base))
let opts = MergeOptions {
strategy: MergeStrategy::TaskArithmetic,
scales: Some(vec![0.7, 0.3]),
base_model: Some("base.safetensors".into()),
..Default::default()
};
// DELLA: adaptive drop rate proportional to magnitude
let opts = MergeOptions {
strategy: MergeStrategy::Della,
drop_rate: 0.7,
base_model: Some("base.safetensors".into()),
..Default::default()
};
// SCE: variance-adaptive per-tensor weighting
let opts = MergeOptions {
strategy: MergeStrategy::Sce,
weights: Some(vec![0.5, 0.5]),
..Default::default()
};
| Field | Type | Default | Used By |
|---|
scales | Option<Vec<f32>> | None (all 1.0) | TaskArithmetic, Breadcrumbs |
outlier_k | f32 | 3.0 | Breadcrumbs |
| Test | Property |
|---|
| FALSIFY-MERGE-ADV-001 | All strategies produce finite results |
| FALSIFY-MERGE-ADV-002 | Task arithmetic with zero scale returns base |
| FALSIFY-MERGE-ADV-003 | SCE result bounded by input values |
cargo run --example advanced_merge