Hyperparameter Optimization Albert-Ludwigs-Universitt Freiburg - - PowerPoint PPT Presentation

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Hyperparameter Optimization Albert-Ludwigs-Universitt Freiburg - - PowerPoint PPT Presentation

Surrogate Benchmarks for Hyperparameter Optimization Albert-Ludwigs-Universitt Freiburg Holger Hoos Katharina Eggensperger Kevin Leyton-Brown Frank Hutter University of British Columbia University of Freiburg {hoos,kevinlb}@cs.ubc.ca


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Albert-Ludwigs-Universität Freiburg

Surrogate Benchmarks for Hyperparameter Optimization

Katharina Eggensperger Frank Hutter

University of Freiburg {eggenspk,fh}@cs.uni-freiburg.de

Holger Hoos Kevin Leyton-Brown

University of British Columbia {hoos,kevinlb}@cs.ubc.ca

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Albert-Ludwigs-Universität Freiburg

Evaluation of Methods for Hyperparameter Optimization is expensive !

Problem:

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  • Benchmarking Hyperparameter Optimization

Methods

  • Constructing Surrogates
  • Using Surrogate Benchmarks

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Outline

MetaSEL’14

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SLIDE 4
  • Benchmarking Hyperparameter Optimization

Methods

  • Constructing Surrogates
  • Using Surrogate Benchmarks

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Outline

MetaSEL’14

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Bayesian Optimization Methods

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Configuration space Λ

Run algorithm with configuration λi

λi

Optimizer

Uses internal model M

Performance f(λi)

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  • Standard benchmark problems
  • Easy-to-use software

Then:

  • Run each optimizer on each benchmark X

multiple times

MetaSEL’14

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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What do we need for an empirical comparison

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  • Standard benchmark problems
  • Easy-to-use software

Then:

  • Run each optimizer on each benchmark X

multiple times

MetaSEL’14

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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What do we need for an empirical comparison

Evaluation of X is expensive

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MetaSEL’14

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Benchmarking hyperparameter

  • ptimization methods

Neural Network, configuration space Λ:

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MetaSEL’14

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Benchmarking hyperparameter

  • ptimization methods

Neural Network, configuration space Λ: categorical hyperparameter

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MetaSEL’14

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Benchmarking hyperparameter

  • ptimization methods

Neural Network, configuration space Λ: conditional hyperparameter

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Benchmarking hyperparameter optimization methods

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Neural network

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Benchmarking hyperparameter optimization methods

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Neural network

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SLIDE 13
  • Benchmarking Hyperparameter Optimization

Methods

  • Constructing Surrogates
  • Using Surrogate Benchmarks

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Outline

MetaSEL’14

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Surrogate Benchmark 𝑌′

  • cheap-to-evaluate
  • Can be used like the real benchmark X
  • Behaves like X

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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𝑌

Configuration 𝜇 Performance 𝑔(𝜇)

MetaSEL’14

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Surrogate Benchmark 𝑌′

  • cheap-to-evaluate
  • Can be used like the real benchmark X
  • Behaves like X

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Regression model 𝑌′

Configuration 𝜇 Performance 𝑔(𝜇)

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Constructing a Surrogate for Benchmark X

  • 1. Collect data
  • 2. Choose a regression model
  • 3. Train and store model

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Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Training data: 𝜇1, 𝑔 𝜇1 , … , 𝜇𝑜, 𝑔 𝜇𝑜

  • Dense sampling in high performance regions
  • Good overall coverage

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Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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  • 1. Collect data for benchmark X
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Training data: 𝜇1, 𝑔 𝜇1 , … , 𝜇𝑜, 𝑔 𝜇𝑜

  • Dense sampling in high performance regions
  • Good overall coverage

MetaSEL’14

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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  • 1. Collect data for benchmark X

Run optimizers on benchmark X

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Training data: 𝜇1, 𝑔 𝜇1 , … , 𝜇𝑜, 𝑔 𝜇𝑜

  • Dense sampling in high performance regions
  • Good overall coverage

MetaSEL’14

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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  • 1. Collect data for benchmark X

Run optimizers on benchmark X Run random search on benchmark X

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  • 2. Choice of Regression Models

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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SVM K-nearest neighbour Gradient Boosting Random Forests Gaussian Processes Linear Regression Bayesian Neural Network Ridge Regression

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  • 2. Choice of Regression Models

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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SVM K-nearest neighbour Gradient Boosting Random Forests Gaussian Processes Linear Regression Bayesian Neural Network Ridge Regression

MetaSEL’14

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  • 2. Choice of Regression Models

Can we quantify the performance of a new

  • ptimizer?
  • Leave-one-optimizer-out setting
  • Train model on data gathered by all but one
  • ptimizer
  • Test on remaining data

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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  • 2. Choice of Regression Models

Leave-one-optimizer-out setting

Neural Network True performance Random forest prediction

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MetaSEL’14

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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  • 2. Choice of Regression Models

Leave-one-optimizer-out setting

Neural Network Random Forest

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MetaSEL’14

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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  • 2. Choice of Regression Models

Leave-one-optimizer-out setting

Neural Network Gaussian Process k-nearest-neighbour Gradient Boosting nuSVR Random Forest

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  • 2. Choice of Regression Models

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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SVM K-nearest neighbour Gradient Boosting Random Forests Gaussian Processes Linear Regression Bayesian Neural Network Ridge Regression

MetaSEL’14

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  • Benchmarking Hyperparameter Optimization

Methods

  • Constructing Surrogates
  • Using Surrogate Benchmarks

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

19

Outline

MetaSEL’14

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Using Surrogate Benchmarks

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Neural Network

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Using Surrogate Benchmarks

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Real Benchmark

Neural Network

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Using Surrogate Benchmarks

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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GP-based benchmark RF-based benchmark Real Benchmark

Neural Network

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Using Surrogate Benchmarks

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Real Benchmark GP-based benchmark RF-based benchmark

Neural Network

40h <200s <200s One optimization run: Whole comparison: 50d <1.5h <1.5h

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  • Extensive testing at early development stages
  • Fast comparison of different hyperparameter
  • ptimization methods
  • Metaoptimization of existing hyperparameter
  • ptimization methods

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Applications

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Conclusion

Can we construct cheap-to evaluate and realistic hyperparameter optimization benchmarks?

Yes, based on random forests and

Gaussian process regression models 

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Conclusion

Can we construct cheap-to evaluate and realistic hyperparameter optimization benchmarks?

Yes, based on random forests and

Gaussian process regression models But, some work needs to be done for high dimensional benchmarks.

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Albert-Ludwigs-Universität Freiburg

Thank you for your attention

This presentation was supported by an ECCAI travel award and the ECCAI sponsors

More information on hyperparameter optimization benchmarks can be found on automl.org/hpolib

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Regression models

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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Benchmarks

Surrogates for Hyperparameter Optimization Benchmarks – Eggensperger, Hutter, Hoos, and Leyton-Brown

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