State-of-art minibatches via novel DPP kernels: discretization, wavelets, and rough objectives
Summary
This research introduces novel Determinantal Point Processes (DPPs) based on wavelets for generating efficient minibatches and coresets in machine learning, addressing challenges in constructing DPPs with strong variance reduction properties and converting continuous DPPs to discrete kernels. The authors propose new wavelet-based DPPs on Euclidean space that offer provably better accuracy guarantees, specifically achieving a standard error of $n^{-(1/2+1/d)}$ for $C^1$ functions, outperforming previous rates of $n^{-(1/2+1/(2d))}$ for multivariate orthogonal polynomial ensembles (OPEs). A general pipeline is presented to convert these continuous DPPs into discrete kernels, preserving variance decay and revealing a low-rank decomposition for computationally inexpensive sampling. This method extends DPP-based improvements to ML tasks with arbitrarily low regularity objective functions, demonstrating superior performance in k-means coreset construction and stochastic gradient descent (SGD) with non-smooth hinge loss on synthetic trimodal and MNIST datasets.
Key takeaway
For research scientists developing or applying subsampling techniques in machine learning, this work provides a robust framework for improving minibatch and coreset efficiency. You should explore integrating wavelet-based DPPs, particularly the Haar or Daubechies-2 variants, into your sampling strategies. This approach offers superior variance reduction and computational efficiency, especially beneficial when dealing with non-smooth objective functions or rough data, potentially leading to faster convergence and more accurate models in applications like k-means and SGD.
Key insights
Wavelet-based DPPs and a novel discretization pipeline significantly enhance minibatch and coreset sampling efficiency for diverse ML tasks.
Principles
- Continuous DPPs are more analytically tractable.
- Variance decay rates can adapt to function regularity.
- Low-rank decomposition enables efficient DPP sampling.
Method
A general pipeline converts continuous wavelet-based DPPs into discrete kernels, preserving variance decay and providing a low-rank decomposition for efficient sampling, applicable even to non-smooth objective functions.
In practice
- Use wavelet DPPs for k-means coreset construction.
- Apply wavelet DPPs to SGD with non-smooth loss functions.
- Consider Haar or Daubechies-2 wavelets for improved performance.
Topics
- Determinantal Point Processes
- Wavelet Kernels
- Continuous-to-Discrete Kernel Conversion
- Variance Reduction
- Minibatch Optimization
Code references
Best for: Research Scientist, AI Scientist, Machine Learning Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by stat.ML updates on arXiv.org.