“…Functional data analysis (FDA) is the branch of statistics that deals with observations varying over a continuous parameter, such as curves, surfaces, and other types of functions (Cuevas 2014;Wang, Chiou, and Müller 2016). These types of data appear in many different fields, such as biology (Cremona, Xu, Makova, Reimherr, Chiaromonte, and Madrigal 2019), demographics (Hyndman and Shahid Ullah 2007), economics (Frois Caldeira, Gupta, Suleman, and Torrent 2020), energy security (Gong, Wang, and Lin 2021), genomics (Leng and Müller 2006;Chen, Cremona, Qi, Mitra, Chiaromonte, and Makova 2020), medicine (Sørensen, Goldsmith, and Sangalli 2013;Ferrando, Ventura-Campos, and Epifanio 2020;Horsley, Ramsay, Ditto, and Da Costa 2021), meteorology (Beyaztas and Yaseen 2019), oceanography (Assunção et al 2020), traffic control (Wagner-Muns, Guardiola, Samaranayke, and Kayani 2018;Hu, Yuan, Zhu, Yang, and Xie 2019), and other areas of application (Ullah and Finch 2013). The functional nature of these data and, in particular, their continuous structure, entails important differences with respect to the classical multivariate statistics.…”