Introduction to R programming using R studio-Beginner Basics

R is case sensitive

# is comment

(Rstudion Code menu->comment/Uncomment option)

To clear Rstudio console

Ctrl+L

To install package MASS

install.packages("MASS")

Alt hypen to get <- in R

to create a vector of 3 elements    

sample <- c(2,1,5.8)

captaincy <- data.frame(namesVector, YVector, playedVector)

1. create dataframe

2. access parts in dataframe

digits=2

mean(captaincy$y,ratio)

write.csv(captaincy,"Newcap.csv",row.names=FALSE)

newCap = read.csv("/../..1.csv")

View(newCap)

inbuilt dataset CO2

View(CO2)

> mean(CO2$conc)

[1] 435

> median(CO2$uptake)

[1] 28.3

> plot(CO2$Plant,CO2$uptake,type='l')

To check the packages installed in R type

library()

To load a package

library(MASS)

ctrl+shift+n to create new R script

ctrl+shift+enter in scipt window to run

Highlight a code and press ctrl+Enter to run only the selected part

sum(matrixA)

colSums(matrixA)

rowSums(matrixA)

To add new row in dataframe

captaincy <- rbind(captaincy, data.frame(name="kohli",Y=2016, played=30,won =20, lost =9,victory=20/30)

cbind is used to add new column to data frame

defeat=captaincy$lost/captaincy$played

captaincy<-cbind(captaincy,defeat)

CaptaincyOne <- read.csv("c.csv")

class(CaptaincyOne)

typeof(CaptaincyOne)  #to get to know about type of data

help(typeof)  #to know more about type of

head(CaptaincyOne,2) # top 2 rows will be displayed

tail(CaptaincyOne,2) # last 2 rows will be displayed

str(CaptaincyOne,2) # structural information  will be displayed

To merge two data frames

c<-merge(CaptaincyOne,CaptaincyTwo, by="names")

To read notepad file

t=read.table("one.txt")

Commonly used R objects are

1. vector

2. Lists

3. Matrices

4. Factors

5. Data Frames

Atomic vector types

logic

integer

numeric

complex 

character

Factor are often referred as categorical variables

Factors have levels

u can convert int to factors

f<factor(fa)

To display levels of factor variable f

levels(f)

as.matrix will convert into matrix

List can contain mixed data type elements

atomic vector has similar data type elements

my<-c(1:5)

list elements can be accesssed using index

mylist[[2]],[,3]  2nd row 3rd column

mylist[][3] indicates all rows 3rd column

to merge two lists l1 and l2

merge.list <- c(l1,l2)

To plot histogram

data <- read.csv("C:/Users/SARVANI/Desktop/rProjects/moviesData.csv")

dim(data)

hist(data$runtime, main = "Distibution of movies",xlab="runtime", xlim=c(0,300),col="blue"   )

to plot pie chart

g <- table(data$genre)

pie(g)

to plot barchart

barplot