20. Low-Rank Adapters (LoRA)
Learning objectives
- Motivate dimension reduction
- Discuss LoRA
- Introduce DoRA
Palmer Penguins

Allison Horst
SVD

SVD
Update Rule
W1=Wpre+ΔW0W2=W1+ΔW1W3=W2+ΔW2... ...Wout
Freezing the Pre-Training Weights
Wout=Wpre+∑i=0ΔWi
Fine Tuning

fine tuning scheme
Dimensionality Reduction

matrix factorization
Speed versus Complexity Trade-Off
smaller rank r
- fewer parameters
- faster training
- lower compute
larger rank r
- more likely to capture task-specific information
DoRA from Vectors
Weight-Decomposed Low-Rank Adaptation
- m: magnitude vector
- V: directional matrix
![]()
vectors!
DoRA Decomposition
W′=m⋅W0+BA||W0+BA||c
![]()
DoRA decomposition
DoRA Workflow
![]()
DoRA workflow
20. Low-Rank Adapters (LoRA)