1. A data processing apparatus comprising: a first unsupervised learning process unit that classifies data of a first data group according to unsupervised learning, to perform dimension reduction for the first data group and to obtain first classified data; a second unsupervised learning process unit that classifies data of a second data group according to the unsupervised learning, to perform dimension reduction for the second data group and to obtain a second classified data group; and a supervised learning process unit that performs supervised learning using, as a teacher, 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.