Part 1

mtcars data set

data("mtcars")
colnames(mtcars)
##  [1] "mpg"  "cyl"  "disp" "hp"   "drat" "wt"   "qsec" "vs"   "am"   "gear"
## [11] "carb"
mtcars3<-mtcars[,1:3]
mtcarsk3<-kmeans(mtcars3,centers=3)
mtcarsk3$size
## [1]  8 16  8
mtcarsk3$centers
##       mpg   cyl     disp
## 1 14.6000 8.000 399.1250
## 2 24.5000 4.625 122.2937
## 3 16.7625 7.500 279.1750
mtcarsk3$cluster
##           Mazda RX4       Mazda RX4 Wag          Datsun 710 
##                   2                   2                   2 
##      Hornet 4 Drive   Hornet Sportabout             Valiant 
##                   3                   1                   3 
##          Duster 360           Merc 240D            Merc 230 
##                   1                   2                   2 
##            Merc 280           Merc 280C          Merc 450SE 
##                   2                   2                   3 
##          Merc 450SL         Merc 450SLC  Cadillac Fleetwood 
##                   3                   3                   1 
## Lincoln Continental   Chrysler Imperial            Fiat 128 
##                   1                   1                   2 
##         Honda Civic      Toyota Corolla       Toyota Corona 
##                   2                   2                   2 
##    Dodge Challenger         AMC Javelin          Camaro Z28 
##                   3                   3                   1 
##    Pontiac Firebird           Fiat X1-9       Porsche 914-2 
##                   1                   2                   2 
##        Lotus Europa      Ford Pantera L        Ferrari Dino 
##                   2                   1                   2 
##       Maserati Bora          Volvo 142E 
##                   3                   2
plot.new()
selectedData <- mtcars[, c("mpg","qsec")]
clusters <- kmeans(selectedData, 3)
plot(x=selectedData[,1], y=selectedData[,2],
         col = mtcarsk3$cluster,
         pch = 20, cex = 3,
         main = paste("qsec", "vs.", "mpg"),
         xlab = "mpg",
         ylab = "qsec")
points(mtcarsk3$centers, pch = 4, cex = 2, lwd = 4)
abline(lm(selectedData[,2] ~ selectedData[,1]))