| d1=read.table("student-mat.csv",sep=";",header=TRUE) | |
| d2=read.table("student-por.csv",sep=";",header=TRUE) | |
| d3=merge(d1,d2,by=c("school","sex","age","address","famsize","Pstatus","Medu","Fedu","Mjob","Fjob","reason","nursery","internet")) | |
| print(nrow(d3)) # 382 students | |