Papers › Gradient Boosted Normalizing Flows

Gradient Boosted Normalizing Flows

27 Feb 2020NeurIPS 2020 12arXiv:2002.11896archive 2025-07-28

Robert Giaquinto, Arindam Banerjee

By chaining a sequence of differentiable invertible transformations, normalizing flows (NF) provide an expressive method of posterior approximation, exact density evaluation, and sampling. The trend in normalizing flow literature has been to devise deeper, more complex transformations to achieve greater flexibility. We propose an alternative: Gradient Boosted Normalizing Flows (GBNF) model a density by successively adding new NF components with gradient boosting. Under the boosting framework, each new NF component optimizes a sample weighted likelihood objective, resulting in new components that are fit to the residuals of the previously trained components. The GBNF formulation results in a mixture model structure, whose flexibility increases as more components are added. Moreover, GBNFs offer a wider, as opposed to strictly deeper, approach that improves existing NFs at the cost of additional training---not more complex transformations. We demonstrate the effectiveness of this technique for density estimation and, by coupling GBNF with a variational autoencoder, generative modeling of images. Our results show that GBNFs outperform their non-boosted analog, and, in some cases, produce better results with smaller, simpler flows.

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ActNorm1d robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository ran MIT (permissive) · 7315468727393ef4 · report
ActNorm2d robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository ran · metamorphic tier: deterministic MIT (permissive) · 5dfed0f3161fd4b1 · report
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Conv2d robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository ran MIT (permissive) · 2d7d6fd92e4989a5 · report
Conv2dZeros robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository ran · metamorphic tier: invariant MIT (permissive) · eeed4e16d893cea5 · report
InvertibleConv1x1 robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository ran · metamorphic tier: deterministic MIT (permissive) · 5c8a917425f0def4 · report
LinearZeros robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository ran · metamorphic tier: invariant MIT (permissive) · 11e0e1eaee63a699 · report
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RealNVP robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository ran · metamorphic tier: deterministic MIT (permissive) · 55233dad2a63c90e · report
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ResidualNet robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository ran · metamorphic tier: invariant MIT (permissive) · 28dd15935b6ad2c2 · report
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log_normal_diag robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository ran · our draft was wrong fingerprinted MIT (permissive) · de88c452ca85eb2d · report
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BoostedFlow robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository unverified MIT (permissive) · 639270ba7c0b6ccd · report
ConvNet robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository unverified MIT (permissive) · 85e265af1f8b4721 · report
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Glow robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository unverified MIT (permissive) · 832c9c612efadf21 · report
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_ActNorm robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository unverified MIT (permissive) · 0e3e13be358d4e88 · report
_Dequantization robert-giaquinto/gradient-boosted-normalizing-flows/models/boosted_flow.py official repository unverified MIT (permissive) · 1ec304d03cf1726b · report
epoch_reporting robert-giaquinto/gradient-boosted-normalizing-flows/density_experiment.py official repository unverified MIT (permissive) · ebb3df3128ed7f4a · report

Tasks

Density EstimationVariational Inference

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Methods

Normalizing FlowsStochastic Gradient Variational Bayes

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