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 bayesianoptimization



Supplementary Informationfor: FastMatrixSquare RootswithApplicationstoGaussianProcessesand BayesianOptimization

Neural Information Processing Systems

We note that all methods incur some sampling error, regardless of the subset size (N). In Fig. S6 we plot the learned hyperparameters of the Precipitation SVGP models: 1)o2 (the kernel outputscale)--which roughly corresponds to variance explained as "signal" in the data; 2)ฯƒ2obs--which roughly corresponds to variance explained away as observational noise; and 3)ฮฝ (degreesoffreedom)--which controls thetailsofthenoisemodel (lowerฮฝ corresponds toheavier tails). As M increases, we find that the observational noise parameter decreases by a factor of 4--downfrom 0.19to0.05--whilethe Fig. S7 is a histogram displaying the msMINRES iterations needed to achieve a relative residual of10 3 when training aM = 5,000SVGP model on the 3droad dataset (subsampled to30,000 datapoints). AsM increases, the kernel outputscale (left) also increases.



Multi-StepBudgetedBayesianOptimization withUnknownEvaluationCosts

Neural Information Processing Systems

To overcome the shortcomings of existing approaches, we propose the budgeted multi-step expected improvement, a non-myopic acquisition function that generalizes classical expected improvement to the setting of heterogeneous and unknown evaluation costs.



CalibrationofSharedEquilibriainGeneralSum PartiallyObservableMarkovGames

Neural Information Processing Systems

We consider a general sum partially observableMarkovgamewhere agents ofdifferent types share asingle policy network, conditioned on agent-specific information. This paper aims at i) formally understanding equilibria reached by such agents, and ii) matching emergent phenomena ofsuch equilibria toreal-worldtargets. Parameter sharing with decentralized execution has been introduced as an efficient way to train multiple agents using a single policy network.



Seeing Numbers: Bayesian Optimisation of a LightGBM model

#artificialintelligence

In a classic case of "be careful what you search for," reading a couple of online articles on model hyper-parameter optimisation has lead to my news feed being bombarded with how-to guides guaranteeing "the most powerful model possible" "in a few easy steps." What I do notice however, is that few articles actually mention that hyper-parameter tuning is only part of the process and is not a silver bullet solution for predictive power. Even fewer articles mention that gains in predictive power from hyper-parameter optimisation are modest and are likely less than gains from decent feature engineering. LightGBM is a gradient boosting framework which uses tree-based learning algorithms. It is an example of an ensemble technique which combines weak individual models to form a single accurate model.


fmfn/BayesianOptimization

#artificialintelligence

This is a constrained global optimization package built upon bayesian inference and gaussian process, that attempts to find the maximum value of an unknown function in as few iterations as possible. This technique is particularly suited for optimization of high cost functions, situations where the balance between exploration and exploitation is important. With the release of version 1.0.0 a number of API breaking changes were introduced. I understand this can be a headache for some, but these were necessary changes that needed to be done and ultimately made the package better. If you have used this package in the past I suggest you take the basic and advanced tours (found in the examples folder) in order to familiarize yourself with the new API.