data("mtcars")
head(mtcars,10)
## mpg cyl disp hp drat wt qsec vs am gear carb
## Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
## Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4
## Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
## Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1
## Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2
## Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1
## Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
## Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
## Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
## Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4
tail(mtcars,5)
## mpg cyl disp hp drat wt qsec vs am gear carb
## Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.9 1 1 5 2
## Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.5 0 1 5 4
## Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.5 0 1 5 6
## Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.6 0 1 5 8
## Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.6 1 1 4 2
names(mtcars)
## [1] "mpg" "cyl" "disp" "hp" "drat" "wt" "qsec" "vs" "am" "gear"
## [11] "carb"
mtcars$brand=row.names(mtcars)
str(mtcars)
## 'data.frame': 32 obs. of 12 variables:
## $ mpg : num 21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ...
## $ cyl : num 6 6 4 6 8 6 8 4 4 6 ...
## $ disp : num 160 160 108 258 360 ...
## $ hp : num 110 110 93 110 175 105 245 62 95 123 ...
## $ drat : num 3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ...
## $ wt : num 2.62 2.88 2.32 3.21 3.44 ...
## $ qsec : num 16.5 17 18.6 19.4 17 ...
## $ vs : num 0 0 1 1 0 1 0 1 1 1 ...
## $ am : num 1 1 1 0 0 0 0 0 0 0 ...
## $ gear : num 4 4 4 3 3 3 3 4 4 4 ...
## $ carb : num 4 4 1 1 2 1 4 2 2 4 ...
## $ brand: chr "Mazda RX4" "Mazda RX4 Wag" "Datsun 710" "Hornet 4 Drive" ...
mtcars[1,]
## mpg cyl disp hp drat wt qsec vs am gear carb brand
## Mazda RX4 21 6 160 110 3.9 2.62 16.46 0 1 4 4 Mazda RX4
mtcars[,2]
## [1] 6 6 4 6 8 6 8 4 4 6 6 8 8 8 8 8 8 4 4 4 4 8 8 8 8 4 4 4 8 6 8 4
mtcars[2,3]
## [1] 160
mtcars$cyl
## [1] 6 6 4 6 8 6 8 4 4 6 6 8 8 8 8 8 8 4 4 4 4 8 8 8 8 4 4 4 8 6 8 4
names=c("Ajay","Vijay","Rajay","Jayesh")
grepl("jay",names)
## [1] TRUE TRUE TRUE FALSE
ifelse(grepl("jay",names),"Yay its Jay", " Oh no where is Jay")
## [1] "Yay its Jay" "Yay its Jay" "Yay its Jay"
## [4] " Oh no where is Jay"
mtcars$type=paste(mtcars$cyl)
head(mtcars)
## mpg cyl disp hp drat wt qsec vs am gear carb
## Mazda RX4 21.0 6 160 110 3.90 2.620 16.46 0 1 4 4
## Mazda RX4 Wag 21.0 6 160 110 3.90 2.875 17.02 0 1 4 4
## Datsun 710 22.8 4 108 93 3.85 2.320 18.61 1 1 4 1
## Hornet 4 Drive 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1
## Hornet Sportabout 18.7 8 360 175 3.15 3.440 17.02 0 0 3 2
## Valiant 18.1 6 225 105 2.76 3.460 20.22 1 0 3 1
## brand type
## Mazda RX4 Mazda RX4 6
## Mazda RX4 Wag Mazda RX4 Wag 6
## Datsun 710 Datsun 710 4
## Hornet 4 Drive Hornet 4 Drive 6
## Hornet Sportabout Hornet Sportabout 8
## Valiant Valiant 6
str(mtcars)
## 'data.frame': 32 obs. of 13 variables:
## $ mpg : num 21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ...
## $ cyl : num 6 6 4 6 8 6 8 4 4 6 ...
## $ disp : num 160 160 108 258 360 ...
## $ hp : num 110 110 93 110 175 105 245 62 95 123 ...
## $ drat : num 3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ...
## $ wt : num 2.62 2.88 2.32 3.21 3.44 ...
## $ qsec : num 16.5 17 18.6 19.4 17 ...
## $ vs : num 0 0 1 1 0 1 0 1 1 1 ...
## $ am : num 1 1 1 0 0 0 0 0 0 0 ...
## $ gear : num 4 4 4 3 3 3 3 4 4 4 ...
## $ carb : num 4 4 1 1 2 1 4 2 2 4 ...
## $ brand: chr "Mazda RX4" "Mazda RX4 Wag" "Datsun 710" "Hornet 4 Drive" ...
## $ type : chr "6" "6" "4" "6" ...
library(stringr)
str_dup(names,3)
## [1] "AjayAjayAjay" "VijayVijayVijay" "RajayRajayRajay"
## [4] "JayeshJayeshJayesh"
namq=c("Ajay ","Vijay "," Rajay"," Jay esh ")
str_trim(namq)
## [1] "Ajay" "Vijay" "Rajay" "Jay esh"
str_pad(namq,width=20,side="left")
## [1] " Ajay " " Vijay " " Rajay"
## [4] " Jay esh "
mtcars[mtcars$cyl==8,]
## mpg cyl disp hp drat wt qsec vs am gear carb
## Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2
## Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
## Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3
## Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3
## Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3
## Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4
## Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4
## Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4
## Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2
## AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2
## Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4
## Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2
## Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4
## Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8
## brand type
## Hornet Sportabout Hornet Sportabout 8
## Duster 360 Duster 360 8
## Merc 450SE Merc 450SE 8
## Merc 450SL Merc 450SL 8
## Merc 450SLC Merc 450SLC 8
## Cadillac Fleetwood Cadillac Fleetwood 8
## Lincoln Continental Lincoln Continental 8
## Chrysler Imperial Chrysler Imperial 8
## Dodge Challenger Dodge Challenger 8
## AMC Javelin AMC Javelin 8
## Camaro Z28 Camaro Z28 8
## Pontiac Firebird Pontiac Firebird 8
## Ford Pantera L Ford Pantera L 8
## Maserati Bora Maserati Bora 8
mtcars[mtcars$cyl==8&mtcars$hp>220,]
## mpg cyl disp hp drat wt qsec vs am gear carb
## Duster 360 14.3 8 360 245 3.21 3.570 15.84 0 0 3 4
## Chrysler Imperial 14.7 8 440 230 3.23 5.345 17.42 0 0 3 4
## Camaro Z28 13.3 8 350 245 3.73 3.840 15.41 0 0 3 4
## Ford Pantera L 15.8 8 351 264 4.22 3.170 14.50 0 1 5 4
## Maserati Bora 15.0 8 301 335 3.54 3.570 14.60 0 1 5 8
## brand type
## Duster 360 Duster 360 8
## Chrysler Imperial Chrysler Imperial 8
## Camaro Z28 Camaro Z28 8
## Ford Pantera L Ford Pantera L 8
## Maserati Bora Maserati Bora 8
mtcars[mtcars$cyl==6|mtcars$hp>220,]
## mpg cyl disp hp drat wt qsec vs am gear carb
## Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
## Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4
## Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1
## Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1
## Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
## Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4
## Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4 4
## Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4
## Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4
## Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4
## Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5 6
## Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8
## brand type
## Mazda RX4 Mazda RX4 6
## Mazda RX4 Wag Mazda RX4 Wag 6
## Hornet 4 Drive Hornet 4 Drive 6
## Valiant Valiant 6
## Duster 360 Duster 360 8
## Merc 280 Merc 280 6
## Merc 280C Merc 280C 6
## Chrysler Imperial Chrysler Imperial 8
## Camaro Z28 Camaro Z28 8
## Ford Pantera L Ford Pantera L 8
## Ferrari Dino Ferrari Dino 6
## Maserati Bora Maserati Bora 8
mtcars[mtcars$cyl!=6,]
## mpg cyl disp hp drat wt qsec vs am gear carb
## Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
## Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2
## Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
## Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
## Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
## Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3
## Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3
## Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3
## Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4
## Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4
## Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4
## Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1
## Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2
## Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1
## Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1
## Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2
## AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2
## Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4
## Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2
## Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1
## Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2
## Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2
## Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4
## Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8
## Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2
## brand type
## Datsun 710 Datsun 710 4
## Hornet Sportabout Hornet Sportabout 8
## Duster 360 Duster 360 8
## Merc 240D Merc 240D 4
## Merc 230 Merc 230 4
## Merc 450SE Merc 450SE 8
## Merc 450SL Merc 450SL 8
## Merc 450SLC Merc 450SLC 8
## Cadillac Fleetwood Cadillac Fleetwood 8
## Lincoln Continental Lincoln Continental 8
## Chrysler Imperial Chrysler Imperial 8
## Fiat 128 Fiat 128 4
## Honda Civic Honda Civic 4
## Toyota Corolla Toyota Corolla 4
## Toyota Corona Toyota Corona 4
## Dodge Challenger Dodge Challenger 8
## AMC Javelin AMC Javelin 8
## Camaro Z28 Camaro Z28 8
## Pontiac Firebird Pontiac Firebird 8
## Fiat X1-9 Fiat X1-9 4
## Porsche 914-2 Porsche 914-2 4
## Lotus Europa Lotus Europa 4
## Ford Pantera L Ford Pantera L 8
## Maserati Bora Maserati Bora 8
## Volvo 142E Volvo 142E 4
attach(mtcars)
mtcars[wt>5,]
## mpg cyl disp hp drat wt qsec vs am gear carb
## Cadillac Fleetwood 10.4 8 472 205 2.93 5.250 17.98 0 0 3 4
## Lincoln Continental 10.4 8 460 215 3.00 5.424 17.82 0 0 3 4
## Chrysler Imperial 14.7 8 440 230 3.23 5.345 17.42 0 0 3 4
## brand type
## Cadillac Fleetwood Cadillac Fleetwood 8
## Lincoln Continental Lincoln Continental 8
## Chrysler Imperial Chrysler Imperial 8
table(cyl)
## cyl
## 4 6 8
## 11 7 14
table(gear)
## gear
## 3 4 5
## 15 12 5
summary(mpg)
## Min. 1st Qu. Median Mean 3rd Qu. Max.
## 10.40 15.42 19.20 20.09 22.80 33.90
library(data.table)
mtcars2=data.table(mtcars)
mtcars2[wt>5,mean(mpg),]
## [1] 11.83333
mtcars2[wt>4&wt<5,mean(mpg),]
## [1] 16.4
cor(mpg,wt)
## [1] -0.8676594
str_trim(names)
## [1] "Ajay" "Vijay" "Rajay" "Jayesh"