zero division error when using ei utility function

bayesian-optimization / BayesianOptimization

A Python implementation of global optimization with gaussian processes.

https://bayesian-optimization.github.io/BayesianOptimization/index.html

MIT License

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zero division error when using ei utility function #516

Closed Yoonho-Na closed 3 weeks ago

Yoonho-Na commented 4 weeks ago

Describe the bug Using bayesian-optimization==1.4.3 results in bayes_opt/util.py:169: RuntimeWarning: divide by zero encountered in true_divide z = a / std.

I used utility function like this ei = UtilityFunction(kind="ei", xi=1e-1)

Screenshots

till-m commented 4 weeks ago

Hi @Yoonho-Na,

It looks like the GP predicts a standard deviation of 0, which can happen because of many things. Without more information we can't really tell you what exactly is the cause here.

till-m commented 3 weeks ago

I will close this issue for now. Feel free to reopen with more information.