"The books of Clavius were translated into Chinese, by one of his students Matteo Ricci "Li Madou" (1552-1610), and his influence for the development of science in China was crucial." Costantino Sigismondi, Christopher Clavius astronomer and mathematician
Apparently Francesco Pellos used the decimal point in his Compendio del Abaco already around 1492 but was much less known than Clavius. Jekuthiel Ginsburg, "On the early history of the decimal point", American Mathematical Monthly 35 (1928) 347–349.