Basics of R

This document will detail the basic functionality of R. In order to create a new project:

  1. Click on File.
  2. New Project.
  3. Create a new directory.
  4. Browse to the place where you want to create the new project.
  5. If required create a new folder.
  6. Click Create Project.
  7. File -> New File -> R Script -> Save as “whatever_the_name”.
  8. Now, you are all set.

Let’s start from inbuilt datset in R titled “mtcars”

data(mtcars)
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
write.csv(mtcars, "mtcars_new.csv") #This piece of code will save your mtcars_new file in the working directory

#Read the csv file into R
data <- read.csv("mtcars_new.csv")

max(data$mpg) #Maximum Value in the mpg variable in the data file 
## [1] 33.9
min(data$mpg) #Minimum Value in the mpg variable in the data file
## [1] 10.4
data[data$mpg > 10,] #This code will print all the rows that have a value of mpg greater than 10 and all the columns. Blank after 'comma' means print all the rows
##                      X  mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## 1            Mazda RX4 21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## 2        Mazda RX4 Wag 21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## 3           Datsun 710 22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## 4       Hornet 4 Drive 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## 5    Hornet Sportabout 18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## 6              Valiant 18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## 7           Duster 360 14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## 8            Merc 240D 24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## 9             Merc 230 22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## 10            Merc 280 19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## 11           Merc 280C 17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## 12          Merc 450SE 16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## 13          Merc 450SL 17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## 14         Merc 450SLC 15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## 15  Cadillac Fleetwood 10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## 16 Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## 17   Chrysler Imperial 14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## 18            Fiat 128 32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## 19         Honda Civic 30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## 20      Toyota Corolla 33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
## 21       Toyota Corona 21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## 22    Dodge Challenger 15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## 23         AMC Javelin 15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## 24          Camaro Z28 13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## 25    Pontiac Firebird 19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## 26           Fiat X1-9 27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## 27       Porsche 914-2 26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## 28        Lotus Europa 30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## 29      Ford Pantera L 15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## 30        Ferrari Dino 19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## 31       Maserati Bora 15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## 32          Volvo 142E 21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
data[data$mpg < 25,]
##                      X  mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## 1            Mazda RX4 21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## 2        Mazda RX4 Wag 21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## 3           Datsun 710 22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## 4       Hornet 4 Drive 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## 5    Hornet Sportabout 18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## 6              Valiant 18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## 7           Duster 360 14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## 8            Merc 240D 24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## 9             Merc 230 22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## 10            Merc 280 19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## 11           Merc 280C 17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## 12          Merc 450SE 16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## 13          Merc 450SL 17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## 14         Merc 450SLC 15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## 15  Cadillac Fleetwood 10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## 16 Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## 17   Chrysler Imperial 14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## 21       Toyota Corona 21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## 22    Dodge Challenger 15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## 23         AMC Javelin 15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## 24          Camaro Z28 13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## 25    Pontiac Firebird 19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## 29      Ford Pantera L 15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## 30        Ferrari Dino 19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## 31       Maserati Bora 15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## 32          Volvo 142E 21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
max(data$mpg)
## [1] 33.9
data_short<-data[data$mpg>15,]
write.csv(data_short, "data_short.csv")



library(plyr)

arrange(data,mpg)
##                      X  mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## 1   Cadillac Fleetwood 10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## 2  Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## 3           Camaro Z28 13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## 4           Duster 360 14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## 5    Chrysler Imperial 14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## 6        Maserati Bora 15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## 7          Merc 450SLC 15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## 8          AMC Javelin 15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## 9     Dodge Challenger 15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## 10      Ford Pantera L 15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## 11          Merc 450SE 16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## 12          Merc 450SL 17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## 13           Merc 280C 17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## 14             Valiant 18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## 15   Hornet Sportabout 18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## 16            Merc 280 19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## 17    Pontiac Firebird 19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## 18        Ferrari Dino 19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## 19           Mazda RX4 21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## 20       Mazda RX4 Wag 21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## 21      Hornet 4 Drive 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## 22          Volvo 142E 21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
## 23       Toyota Corona 21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## 24          Datsun 710 22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## 25            Merc 230 22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## 26           Merc 240D 24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## 27       Porsche 914-2 26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## 28           Fiat X1-9 27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## 29         Honda Civic 30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## 30        Lotus Europa 30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## 31            Fiat 128 32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## 32      Toyota Corolla 33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
data[order(data$mpg,decreasing=TRUE),] #Data will be arranged in decreasing order
##                      X  mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## 20      Toyota Corolla 33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
## 18            Fiat 128 32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## 19         Honda Civic 30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## 28        Lotus Europa 30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## 26           Fiat X1-9 27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## 27       Porsche 914-2 26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## 8            Merc 240D 24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## 3           Datsun 710 22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## 9             Merc 230 22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## 21       Toyota Corona 21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## 4       Hornet 4 Drive 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## 32          Volvo 142E 21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
## 1            Mazda RX4 21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## 2        Mazda RX4 Wag 21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## 30        Ferrari Dino 19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## 10            Merc 280 19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## 25    Pontiac Firebird 19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## 5    Hornet Sportabout 18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## 6              Valiant 18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## 11           Merc 280C 17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## 13          Merc 450SL 17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## 12          Merc 450SE 16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## 29      Ford Pantera L 15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## 22    Dodge Challenger 15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## 14         Merc 450SLC 15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## 23         AMC Javelin 15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## 31       Maserati Bora 15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## 17   Chrysler Imperial 14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## 7           Duster 360 14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## 24          Camaro Z28 13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## 15  Cadillac Fleetwood 10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## 16 Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
data[order(data$mpg,decreasing=FALSE),] #Data will be arranged in increasing order
##                      X  mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## 15  Cadillac Fleetwood 10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## 16 Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## 24          Camaro Z28 13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## 7           Duster 360 14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## 17   Chrysler Imperial 14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## 31       Maserati Bora 15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## 14         Merc 450SLC 15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## 23         AMC Javelin 15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## 22    Dodge Challenger 15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## 29      Ford Pantera L 15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## 12          Merc 450SE 16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## 13          Merc 450SL 17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## 11           Merc 280C 17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## 6              Valiant 18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## 5    Hornet Sportabout 18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## 10            Merc 280 19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## 25    Pontiac Firebird 19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## 30        Ferrari Dino 19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## 1            Mazda RX4 21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## 2        Mazda RX4 Wag 21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## 4       Hornet 4 Drive 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## 32          Volvo 142E 21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
## 21       Toyota Corona 21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## 3           Datsun 710 22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## 9             Merc 230 22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## 8            Merc 240D 24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## 27       Porsche 914-2 26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## 26           Fiat X1-9 27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## 19         Honda Civic 30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## 28        Lotus Europa 30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## 18            Fiat 128 32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## 20      Toyota Corolla 33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
arrange(data,mpg) #Data will be arranged in increasing order
##                      X  mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## 1   Cadillac Fleetwood 10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## 2  Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## 3           Camaro Z28 13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## 4           Duster 360 14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## 5    Chrysler Imperial 14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## 6        Maserati Bora 15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## 7          Merc 450SLC 15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## 8          AMC Javelin 15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## 9     Dodge Challenger 15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## 10      Ford Pantera L 15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## 11          Merc 450SE 16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## 12          Merc 450SL 17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## 13           Merc 280C 17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## 14             Valiant 18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## 15   Hornet Sportabout 18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## 16            Merc 280 19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## 17    Pontiac Firebird 19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## 18        Ferrari Dino 19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## 19           Mazda RX4 21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## 20       Mazda RX4 Wag 21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## 21      Hornet 4 Drive 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## 22          Volvo 142E 21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
## 23       Toyota Corona 21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## 24          Datsun 710 22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## 25            Merc 230 22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## 26           Merc 240D 24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## 27       Porsche 914-2 26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## 28           Fiat X1-9 27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## 29         Honda Civic 30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## 30        Lotus Europa 30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## 31            Fiat 128 32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## 32      Toyota Corolla 33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1