#INSTRUCTIONS: type the commands in R studio - but do not #run them, first ask yourself and note down, what *do you #think* would R say? Only then run them in R studio. This is the #only way to learn simple commands - and have them #memorized so that you can write code without having to check #every single command. Also, use the Data101 laboratory site #and run the codes (always asking yourself FIRST, what #will R say?)
 
 #PRACTICE:
 u<-c(1:10)
 w <-c(1,-1,3)
 u[w>0]
 #what would R say?