2.10 Lab 1: Solutions
x <- seq(2,10,by=2)
y <- c(3,5,7,11,13)
x+y
#> [1] 5 9 13 19 23
x-y
#> [1] -1 -1 -1 -3 -3
x*y
#> [1] 6 20 42 88 130
x/y
#> [1] 0.6666667 0.8000000 0.8571429 0.7272727 0.7692308geometric_mean <- function(x) {
J <- length(x)
res <- prod(x)^(1/J)
res
}
geometric_mean(c(10,8,13))
#> [1] 10.13159the_date <- lubridate::mdy("01-01-1981")
today <- lubridate::mdy("08-23-2021")
today - the_date
#> Time difference of 14844 daysnrow(mtcars) #> [1] 32ncol(mtcars) #> [1] 11colnames(mtcars) #> [1] "mpg" "cyl" "disp" "hp" "drat" "wt" "qsec" "vs" #> [9] "am" "gear" "carb"subset(mtcars, mpg >= 20) #> mpg cyl disp hp drat wt qsec vs am #> Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 #> Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 #> Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 #> Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 #> Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 #> Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 #> Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1 #> Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1 #> Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1 #> Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0 #> Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 1 #> Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 1 #> Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1 #> Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1 #> gear carb #> Mazda RX4 4 4 #> Mazda RX4 Wag 4 4 #> Datsun 710 4 1 #> Hornet 4 Drive 3 1 #> Merc 240D 4 2 #> Merc 230 4 2 #> Fiat 128 4 1 #> Honda Civic 4 2 #> Toyota Corolla 4 1 #> Toyota Corona 3 1 #> Fiat X1-9 4 1 #> Porsche 914-2 5 2 #> Lotus Europa 5 2 #> Volvo 142E 4 2subset(mtcars, (mpg >= 20) & (hp >= 100)) #> mpg cyl disp hp drat wt qsec vs am #> Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 #> Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 #> Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 #> Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1 #> Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1 #> gear carb #> Mazda RX4 4 4 #> Mazda RX4 Wag 4 4 #> Hornet 4 Drive 3 1 #> Lotus Europa 5 2 #> Volvo 142E 4 2subset(mtcars, (cyl >= 6) | (hp >= 100)) #> mpg cyl disp hp drat wt qsec vs #> Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 #> Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 #> Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 #> Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 #> Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 #> Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 #> Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 #> Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 #> Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 #> Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 #> Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 #> Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 #> Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 #> Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 #> Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 #> AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 #> Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 #> Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 #> Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 #> Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 #> Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 #> Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 #> Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 #> am gear carb #> Mazda RX4 1 4 4 #> Mazda RX4 Wag 1 4 4 #> Hornet 4 Drive 0 3 1 #> Hornet Sportabout 0 3 2 #> Valiant 0 3 1 #> Duster 360 0 3 4 #> Merc 280 0 4 4 #> Merc 280C 0 4 4 #> Merc 450SE 0 3 3 #> Merc 450SL 0 3 3 #> Merc 450SLC 0 3 3 #> Cadillac Fleetwood 0 3 4 #> Lincoln Continental 0 3 4 #> Chrysler Imperial 0 3 4 #> Dodge Challenger 0 3 2 #> AMC Javelin 0 3 2 #> Camaro Z28 0 3 4 #> Pontiac Firebird 0 3 2 #> Lotus Europa 1 5 2 #> Ford Pantera L 1 5 4 #> Ferrari Dino 1 5 6 #> Maserati Bora 1 5 8 #> Volvo 142E 1 4 2mtcars[10,] #> mpg cyl disp hp drat wt qsec vs am gear carb #> Merc 280 19.2 6 167.6 123 3.92 3.44 18.3 1 0 4 4# without reversing the order, we would order from lowest to smallest mtcars[rev(order(mtcars$mpg)),] #> mpg cyl disp hp drat wt qsec vs #> Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 #> Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 #> Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 #> Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 #> Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 #> Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 #> Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 #> Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 #> Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 #> Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 #> Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 #> Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 #> Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 #> Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 #> Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 #> Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 #> Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 #> Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 #> Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 #> Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 #> Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 #> Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 #> Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 #> Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 #> AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 #> Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 #> Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 #> Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 #> Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 #> Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 #> Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 #> Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 #> am gear carb #> Toyota Corolla 1 4 1 #> Fiat 128 1 4 1 #> Lotus Europa 1 5 2 #> Honda Civic 1 4 2 #> Fiat X1-9 1 4 1 #> Porsche 914-2 1 5 2 #> Merc 240D 0 4 2 #> Merc 230 0 4 2 #> Datsun 710 1 4 1 #> Toyota Corona 0 3 1 #> Volvo 142E 1 4 2 #> Hornet 4 Drive 0 3 1 #> Mazda RX4 Wag 1 4 4 #> Mazda RX4 1 4 4 #> Ferrari Dino 1 5 6 #> Pontiac Firebird 0 3 2 #> Merc 280 0 4 4 #> Hornet Sportabout 0 3 2 #> Valiant 0 3 1 #> Merc 280C 0 4 4 #> Merc 450SL 0 3 3 #> Merc 450SE 0 3 3 #> Ford Pantera L 1 5 4 #> Dodge Challenger 0 3 2 #> AMC Javelin 0 3 2 #> Merc 450SLC 0 3 3 #> Maserati Bora 1 5 8 #> Chrysler Imperial 0 3 4 #> Duster 360 0 3 4 #> Camaro Z28 0 3 4 #> Lincoln Continental 0 3 4 #> Cadillac Fleetwood 0 3 4