Jawaharlal Nehru Technological University Hyderabad B.Tech III INTRODUCTION TO ANALYTICS (ASSOCIATE ANALYTICS – I) Previous Question Paper (February/March - 2022 - R16)

R programming provides three primary types of loops to execute a block of code repeatedly:

1. repeat loop: Executes a block of code repeatedly until a break statement is encountered. It is an infinite loop unless a condition is explicitly defined to exit.
   repeat { if(condition) break; }
2. while loop: Executes a block of code as long as a specified condition evaluates to TRUE. The condition is checked before each iteration.
   while(condition) { # code to execute }
3. for loop: Iterates over a sequence, such as a vector, list, or array, executing the code block for each element in the sequence.
   for(variable in sequence) { # code to execute }

Outliers can be identified in R using statistical methods like the Interquartile Range (IQR) rule. The process involves calculating the first quartile (Q1), the third quartile (Q3), and the IQR (Q3 - Q1). Data points falling below Q1 - 1.5 * IQR or above Q3 + 1.5 * IQR are considered outliers.

Example implementation:

data <- c(10, 12, 12, 13, 12, 11, 14, 100) # 100 is an outlier
Q1 <- quantile(data, 0.25)
Q3 <- quantile(data, 0.75)
IQR_val <- Q3 - Q1
lower_bound <- Q1 - 1.5 * IQR_val
upper_bound <- Q3 + 1.5 * IQR_val
outliers <- data[data < lower_bound | data > upper_bound]
print(outliers)

Alternatively, the boxplot() function provides a visual representation where outliers are plotted as individual points beyond the whiskers.