“…Correa-Quezada et al (2020) applied the non-parametric method of Kernel density functions in order to analyze the regional growth and convergence processes in the service sector, in Ecuador, through productivity as the reference variable. Xu et al (2017) analyzed the essential relationship established between e-commerce and tourist flow by appealing to kernel density estimation. In their enterprises they took as a model the ecommerce data of Huangshan tourism cloud platform.…”