Function for reading the drug consumption data from the UCI repository
read_drugdata()X first coordinate matrix
Y matrix with response variables (Alcohol,Am,Amyl,Be,Caff,Ca,Choc,Co,Crack,Ex,Heroin,Ke,Le,LSD,Me,Mu,Ni,Semer,VSA)
idx indicator which response variables have a probability between 0.1 and 0.9
Fehrman, E., Muhammad, A. K., Mirkes, E. M., Egan, V., & Gorban, A. N. (2017). The five factor model of personality and evaluation of drug consumption risk. In Data science: innovative developments in data analysis and clustering (pp. 231-242). Springer International Publishing.