Robust Regression for Automatic Fusion Plasma Analysis Based on Generative Modeling

The first step to realize an automatic experimental data analysis for fusion plasma experiments is fitting noisy data of temperature and density spatial profiles, which are routinely obtained. However, it has been difficult to construct algorithms that fit all the data without overfitting and underfitting. In this paper, we show that this difficulty originates from the lack of knowledge of the probability distribution that the measurement data follow. We demonstrate the use of a machine learning technique to estimate the data distribution and to construct an optimal generative model. We show that the fitting algorithm based on the generative modeling outperforms classical heuristic methods in terms of the stability as well as the accuracy.