Slip 16 - E) Consider the inbuilt mtcar dataset i) Subset the vector, “mtcars[,1]“, for values greater than “15.0“. ii) Subset “airquality” for “Ozone” greater than “28“, or “Temp” greater than “70“. Return the first five rows. iii) Subset “airquality” for “Ozone” greater than “100“. Select the columns “Ozone“, “Temp“, “Month” and “Day” only.

Solution:

dim(airquality)

colnames(airquality)

subset(mtcars[,1],mtcars[,1]>15.0)

head(subset(airquality, Ozone>28|Temp>70))

subset(airquality,Ozone>100,select=c(Ozone,Temp,Month,Day))