R Language

What is R? Variables in R Summary of data Box plot Histogram Using Help in R

What is R ? R is a free, cross-platform, open-source statistical analysis language and program. Many statistical functions are already built in

Variables Numeric > a = 49 > sqrt(a) [1] 7 String > a = "The dog ate my homework" > sub("dog","cat",a) [1] "The cat ate my homework“ Logical > a = (1+1==3) > a [1] FALSE

vector: an ordered collection of data of the same type > a = c(1,2,3) To examine the contents of the variable a >a [1] > a*2 [1] > a[2] [1] 2

list: an ordered collection of data of arbitrary types. > d = list(name="john",age=28,married=F) > d$name [1] "john“ > d$age [1] 28

Mean Dataset: > x=c(0,4,15, 1, 6, 3, 20, 5, 8, 1, 3) >y= 1:6 >y [1] The Mean > mean(x) [1] 6 OR > sum(x)/length(x) [1] 6

Median Sort the dataset if it is not sorted >sort(x) [1] The Median > median(x) [1] 4 > median(y) [1] 3.5

Quantiles Q1 > quantile(x,0.25) 25% 2 Q3 > quantile(x,0.75) 75% 7 Quantiles > quantile(x,c(0,0.25,0.5,0.75,1)) 0% 25% 50% 75% 100%

Five Number Summary > summary(x) Min. 1st Qu. Median Mean 3rd Qu. Max

The Spread of the Data Set Range > range(x) [1] 0 20 IQR > IQR(x) [1] 5

Boxplot Standard Boxplot > boxplot(x,range=0) Modified Boxplot > boxplot(x)

Histogram > hist(x) Adding a title > hist(x,main=“ Weight Gain ”) Adding Axis labels >hist(x, main=“Weight Gain”,xlab=“Weight Gain”, ylab =“Frequency”) Change the color >hist(x, main=“Weight Gain”,xlab=“Weight Gain”, ylab =“Frequency”, col=“blue”)

Read CSV > mydata=read.csv("dataset.csv") > mydata Age Income

How to use help in R? R has a very good help system built in. If you know which function you want help with simply use ?_______ with the function in the blank. Ex: ?hist. If you don’t know which function to use, then use help.search(“_______”). Ex: help.search(“histogram”).

Activity 1.Using R language, Answer question 4 from the Tutorial. 2.Export the resulted graphs.