“…As discussed, vectorization methods can be used in input space, however, kernel-based models are another important way to combine PD information with machine learning models [Kwitt et al, 2015]. Since metrics can be modified into kernels, various approaches have been proposed to induce kernel function from PD information [Pun et al, 2022] and into traditional machine learning approaches like PCA and SVM. Topological-based kernel methods have been used successfully in various ways [Zhu et al, 2016;Kwitt et al, 2015], however techniques based on kernel methods suffer from scalability issues [Pun et al, 2022], as training typically scales poorly with the sample number (e.g., roughly cubic in the case of kernel-SVMs).…”