1. A data processing apparatus comprising: a first unsupervised learning process unit that classifies data of a first data group according to unsupervised learning, and that obtains a first classified data group based on the classified first data group by performing dimension reduction for the classified first data group; a second unsupervised learning process unit that classifies data of a second data group according to the unsupervised learning, and that obtains a second classified data group based on the classified second data group by performing dimension reduction for the classified second data group; a supervised learning process unit that performs supervised learning using, as a teacher, both the first classified data group obtained by the first unsupervised learning process unit and the second classified data group obtained by the second unsupervised learning process unit to determine a mapping relation between the first classified data group and the second classified data group; and wherein the first and second unsupervised learning process units are performed independently of each other.