R语言边学边记5-数据的提取

> mtcars

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

Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0

Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0

Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 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

Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0

Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0

Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0

Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0

Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0

Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0

Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0

Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 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

Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0

AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0

Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0

Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 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

Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1

Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1

Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 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

Hornet Sportabout 3 2

Valiant 3 1

Duster 360 3 4

Merc 240D 4 2

Merc 230 4 2

Merc 280 4 4

Merc 280C 4 4

Merc 450SE 3 3

Merc 450SL 3 3

Merc 450SLC 3 3

Cadillac Fleetwood 3 4

Lincoln Continental 3 4

Chrysler Imperial 3 4

Fiat 128 4 1

Honda Civic 4 2

Toyota Corolla 4 1

Toyota Corona 3 1

Dodge Challenger 3 2

AMC Javelin 3 2

Camaro Z28 3 4

Pontiac Firebird 3 2

Fiat X1-9 4 1

Porsche 914-2 5 2

Lotus Europa 5 2

Ford Pantera L 5 4

Ferrari Dino 5 6

Maserati Bora 5 8

Volvo 142E 4 2

> mtcars

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

Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0

Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0

Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 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

Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0

Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0

Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0

Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0

Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0

Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0

Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0

Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 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

Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0

AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0

Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0

Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 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

Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1

Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1

Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 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

Hornet Sportabout 3 2

Valiant 3 1

Duster 360 3 4

Merc 240D 4 2

Merc 230 4 2

Merc 280 4 4

Merc 280C 4 4

Merc 450SE 3 3

Merc 450SL 3 3

Merc 450SLC 3 3

Cadillac Fleetwood 3 4

Lincoln Continental 3 4

Chrysler Imperial 3 4

Fiat 128 4 1

Honda Civic 4 2

Toyota Corolla 4 1

Toyota Corona 3 1

Dodge Challenger 3 2

AMC Javelin 3 2

Camaro Z28 3 4

Pontiac Firebird 3 2

Fiat X1-9 4 1

Porsche 914-2 5 2

Lotus Europa 5 2

Ford Pantera L 5 4

Ferrari Dino 5 6

Maserati Bora 5 8

Volvo 142E 4 2

> mtcars[order(mtcars$mpg),]#排序所有的列，按照mpg排序

mpg cyl disp hp drat wt qsec vs am

Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0

Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0

Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0

Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0

Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0

Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1

Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0

AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0

Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0

Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1

Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0

Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0

Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0

Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0

Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0

Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0

Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 0

Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1

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

Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1

Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0

Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1

Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0

Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0

Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 1

Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 1

Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1

Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1

Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1

Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1

gear carb

Cadillac Fleetwood 3 4

Lincoln Continental 3 4

Camaro Z28 3 4

Duster 360 3 4

Chrysler Imperial 3 4

Maserati Bora 5 8

Merc 450SLC 3 3

AMC Javelin 3 2

Dodge Challenger 3 2

Ford Pantera L 5 4

Merc 450SE 3 3

Merc 450SL 3 3

Merc 280C 4 4

Valiant 3 1

Hornet Sportabout 3 2

Merc 280 4 4

Pontiac Firebird 3 2

Ferrari Dino 5 6

Mazda RX4 4 4

Mazda RX4 Wag 4 4

Hornet 4 Drive 3 1

Volvo 142E 4 2

Toyota Corona 3 1

Datsun 710 4 1

Merc 230 4 2

Merc 240D 4 2

Porsche 914-2 5 2

Fiat X1-9 4 1

Honda Civic 4 2

Lotus Europa 5 2

Fiat 128 4 1

Toyota Corolla 4 1

> mtcars[order(mtcars$mpg),1:3]#按照mpg,排列前三项

mpg cyl disp

Cadillac Fleetwood 10.4 8 472.0

Lincoln Continental 10.4 8 460.0

Camaro Z28 13.3 8 350.0

Duster 360 14.3 8 360.0

Chrysler Imperial 14.7 8 440.0

Maserati Bora 15.0 8 301.0

Merc 450SLC 15.2 8 275.8

AMC Javelin 15.2 8 304.0

Dodge Challenger 15.5 8 318.0

Ford Pantera L 15.8 8 351.0

Merc 450SE 16.4 8 275.8

Merc 450SL 17.3 8 275.8

Merc 280C 17.8 6 167.6

Valiant 18.1 6 225.0

Hornet Sportabout 18.7 8 360.0

Merc 280 19.2 6 167.6

Pontiac Firebird 19.2 8 400.0

Ferrari Dino 19.7 6 145.0

Mazda RX4 21.0 6 160.0

Mazda RX4 Wag 21.0 6 160.0

Hornet 4 Drive 21.4 6 258.0

Volvo 142E 21.4 4 121.0

Toyota Corona 21.5 4 120.1

Datsun 710 22.8 4 108.0

Merc 230 22.8 4 140.8

Merc 240D 24.4 4 146.7

Porsche 914-2 26.0 4 120.3

Fiat X1-9 27.3 4 79.0

Honda Civic 30.4 4 75.7

Lotus Europa 30.4 4 95.1

Fiat 128 32.4 4 78.7

Toyota Corolla 33.9 4 71.1

> mtcars[order(mtcars$mpg,mtcars$cyl),]#mpg数值相同情况下，按照cyl排序(次要关键词)

mpg cyl disp hp drat wt qsec vs am

Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0

Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0

Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0

Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0

Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0

Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1

Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0

AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0

Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0

Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1

Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0

Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0

Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0

Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0

Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0

Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0

Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 0

Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1

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

Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1

Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0

Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0

Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1

Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0

Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0

Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 1

Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 1

Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1

Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1

Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1

Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1

gear carb

Cadillac Fleetwood 3 4

Lincoln Continental 3 4

Camaro Z28 3 4

Duster 360 3 4

Chrysler Imperial 3 4

Maserati Bora 5 8

Merc 450SLC 3 3

AMC Javelin 3 2

Dodge Challenger 3 2

Ford Pantera L 5 4

Merc 450SE 3 3

Merc 450SL 3 3

Merc 280C 4 4

Valiant 3 1

Hornet Sportabout 3 2

Merc 280 4 4

Pontiac Firebird 3 2

Ferrari Dino 5 6

Mazda RX4 4 4

Mazda RX4 Wag 4 4

Volvo 142E 4 2

Hornet 4 Drive 3 1

Toyota Corona 3 1

Datsun 710 4 1

Merc 230 4 2

Merc 240D 4 2

Porsche 914-2 5 2

Fiat X1-9 4 1

Honda Civic 4 2

Lotus Europa 5 2

Fiat 128 4 1

Toyota Corolla 4 1

> mtcars[order(-mtcars$mpg,mtcars$cyl),]#mpg倒序排列，cyl升序

mpg cyl disp hp drat wt qsec vs am

Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1

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

Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1

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

Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0

Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1

Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0

Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0

Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1

Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0

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

Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1

Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0

Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 0

Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0

Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0

Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0

Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0

Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0

Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1

Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0

Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0

AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0

Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1

Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0

Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0

Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0

Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0

Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0

gear carb

Toyota Corolla 4 1

Fiat 128 4 1

Honda Civic 4 2

Lotus Europa 5 2

Fiat X1-9 4 1

Porsche 914-2 5 2

Merc 240D 4 2

Datsun 710 4 1

Merc 230 4 2

Toyota Corona 3 1

Volvo 142E 4 2

Hornet 4 Drive 3 1

Mazda RX4 4 4

Mazda RX4 Wag 4 4

Ferrari Dino 5 6

Merc 280 4 4

Pontiac Firebird 3 2

Hornet Sportabout 3 2

Valiant 3 1

Merc 280C 4 4

Merc 450SL 3 3

Merc 450SE 3 3

Ford Pantera L 5 4

Dodge Challenger 3 2

Merc 450SLC 3 3

AMC Javelin 3 2

Maserati Bora 5 8

Chrysler Imperial 3 4

Duster 360 3 4

Camaro Z28 3 4

Cadillac Fleetwood 3 4

Lincoln Continental 3 4

> library(dplyr)

> arrange(mtcars,mpg,vs)

mpg cyl disp hp drat wt qsec vs am gear carb

1 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4

2 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4

3 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4

4 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4

5 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4

6 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8

7 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3

8 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2

9 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2

10 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4

11 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3

12 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3

13 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4 4

14 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1

15 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2

16 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2

17 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4

18 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5 6

19 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4

20 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4

21 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1

22 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2

23 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1

24 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1

25 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2

26 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2

27 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2

28 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1

29 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2

30 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2

31 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1

32 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1

> arrange(mtcars,-mpg,vs)

mpg cyl disp hp drat wt qsec vs am gear carb

1 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1

2 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1

3 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2

4 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2

5 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1

6 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2

7 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2

8 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1

9 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2

10 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1

11 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1

12 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2

13 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4

14 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4

15 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5 6

16 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2

17 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4

18 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2

19 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1

20 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4 4

21 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3

22 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3

23 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4

24 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2

25 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3

26 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2

27 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8

28 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4

29 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4

30 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4

31 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4

32 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4

> mtcars

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

Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0

Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0

Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 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

Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0

Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0

Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0

Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0

Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0

Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0

Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0

Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 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

Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0

AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0

Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0

Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 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

Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1

Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1

Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 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

Hornet Sportabout 3 2

Valiant 3 1

Duster 360 3 4

Merc 240D 4 2

Merc 230 4 2

Merc 280 4 4

Merc 280C 4 4

Merc 450SE 3 3

Merc 450SL 3 3

Merc 450SLC 3 3

Cadillac Fleetwood 3 4

Lincoln Continental 3 4

Chrysler Imperial 3 4

Fiat 128 4 1

Honda Civic 4 2

Toyota Corolla 4 1

Toyota Corona 3 1

Dodge Challenger 3 2

AMC Javelin 3 2

Camaro Z28 3 4

Pontiac Firebird 3 2

Fiat X1-9 4 1

Porsche 914-2 5 2

Lotus Europa 5 2

Ford Pantera L 5 4

Ferrari Dino 5 6

Maserati Bora 5 8

Volvo 142E 4 2

> #选取子集

> #要求mpg大于等于20，并且vs等于0的数据集

> subset(mtcars,mpg>=20 & vs==0)#需要两个等号，一个等号为赋值0，两个为严格等于0

mpg cyl disp hp drat wt qsec vs am gear carb

Mazda RX4 21 6 160.0 110 3.90 2.620 16.46 0 1 4 4

Mazda RX4 Wag 21 6 160.0 110 3.90 2.875 17.02 0 1 4 4

Porsche 914-2 26 4 120.3 91 4.43 2.140 16.70 0 1 5 2

> subset(mtcars,mpg>=20 & vs==0,hp)

Mazda RX4 110

Mazda RX4 Wag 110

Porsche 914-2 91

> a<-subset(mtcars,mpg>=20 & vs==0)

> a

mpg cyl disp hp drat wt qsec vs am gear carb

Mazda RX4 21 6 160.0 110 3.90 2.620 16.46 0 1 4 4

Mazda RX4 Wag 21 6 160.0 110 3.90 2.875 17.02 0 1 4 4

Porsche 914-2 26 4 120.3 91 4.43 2.140 16.70 0 1 5 2

> subset(a,cyl>4,)

mpg cyl disp hp drat wt qsec vs am gear carb

Mazda RX4 21 6 160 110 3.9 2.620 16.46 0 1 4 4

Mazda RX4 Wag 21 6 160 110 3.9 2.875 17.02 0 1 4 4

> filter(mtcars,mpg>=20,vs==0)#==为严格等于

mpg cyl disp hp drat wt qsec vs am gear carb

1 21 6 160.0 110 3.90 2.620 16.46 0 1 4 4

2 21 6 160.0 110 3.90 2.875 17.02 0 1 4 4

3 26 4 120.3 91 4.43 2.140 16.70 0 1 5 2

> #要求mpg大于等于20，或vs等于0的数据集

> filter(mtcars,mpg>=20|vs==0)#==为严格等于,|为或，&为且

mpg cyl disp hp drat wt qsec vs am gear carb

1 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4

2 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4

3 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1

4 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1

5 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2

6 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4

7 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2

8 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2

9 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3

10 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3

11 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3

12 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4

13 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4

14 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4

15 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1

16 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2

17 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1

18 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1

19 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2

20 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2

21 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4

22 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2

23 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1

24 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2

25 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2

26 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4

27 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5 6

28 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8

29 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2

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