HW 5

Functions

1- Create a function named calculate_area_of_circle that takes one parameter, radius, representing the radius of a circle. The function should calculate and return the area using the formula:

area = 𝜋 × radius^2

Test your function with at least two different radii and print the results.

calculate_area_of_circle <- function (radius) {
area <- pi * radius^2
return(area)
}

radius1 <- 3
radius2 <-10

area1 <- calculate_area_of_circle(radius1)
area2 <- calculate_area_of_circle(radius2)

print(paste("Area of circle with radius", radius1, ":", area1))

## [1] "Area of circle with radius 3 : 28.2743338823081"

print(paste("Area of circle with radius", radius2, ":", area2))

## [1] "Area of circle with radius 10 : 314.159265358979"

2- Write a function called check_temperature that takes a single numeric input temp.

If temp > 30, print “Hot”

If temp >= 15 & temp <= 30, print “Warm”

Otherwise, print “Cold”

Test the function on three different values (e.g., 10, 20, 35).

check_temperature <- function(temp) {
  if (temp> 20) {
    print("Hot") 
  } else if (temp >= 12 & temp <=30) {
    print("Warm")
  } else {
    print("Cold")
  }
}
check_temperature(10)  # Should print "Cold"

## [1] "Cold"

check_temperature(20)  # Should print "Warm"

## [1] "Warm"

check_temperature(35)  # Should print "Hot"

## [1] "Hot"

3- Write a function named sum_odd_numbers that uses a for loop to calculate the sum of all odd numbers from 1 to n. The function should return the total sum.

Test the function with n = 9 and n = 39.

sum_odd_numbers <- function(n) { 
  total <- 0
  for (i in 1:n) {
    if(i %% 2== 1) {
      total <- total + i
    }
  } }

print(paste("Sum of odd numbers up to 9:", sum_odd_numbers(9)))

## [1] "Sum of odd numbers up to 9: "

print(paste("Sum of odd numbers up to 39:", sum_odd_numbers(39)))

## [1] "Sum of odd numbers up to 39: "

EDA

For this section, use the built-in mtcars dataset. Perform the following:

• Check the structure of the dataset.

• Display the summary statistics.

• Check for any missing values.

Write a question about the dataset and answer it using functions you learned in this class. Print the output of the answer.

Classify car horsepower(hp) as High,Medium, and low based on its value

data(mtcars)

classify_hp <- function(hp) {
  if (hp > 200) {
    print("High")
  } else if (hp >= 100 & hp <= 200) {
    print("Medium")
  } else {
    print("Low")
  }
}

classify_hp(90)

## [1] "Low"

classify_hp(150)

## [1] "Medium"

classify_hp(220)

## [1] "High"

for (i in 1:nrow(mtcars)) {
  car_name <- rownames(mtcars)[i]
  hp_class <- classify_hp(mtcars$hp[i])
  print(paste("Car:", car_name, "-Horsepower Category:", hp_class))
}

## [1] "Medium"
## [1] "Car: Mazda RX4 -Horsepower Category: Medium"
## [1] "Medium"
## [1] "Car: Mazda RX4 Wag -Horsepower Category: Medium"
## [1] "Low"
## [1] "Car: Datsun 710 -Horsepower Category: Low"
## [1] "Medium"
## [1] "Car: Hornet 4 Drive -Horsepower Category: Medium"
## [1] "Medium"
## [1] "Car: Hornet Sportabout -Horsepower Category: Medium"
## [1] "Medium"
## [1] "Car: Valiant -Horsepower Category: Medium"
## [1] "High"
## [1] "Car: Duster 360 -Horsepower Category: High"
## [1] "Low"
## [1] "Car: Merc 240D -Horsepower Category: Low"
## [1] "Low"
## [1] "Car: Merc 230 -Horsepower Category: Low"
## [1] "Medium"
## [1] "Car: Merc 280 -Horsepower Category: Medium"
## [1] "Medium"
## [1] "Car: Merc 280C -Horsepower Category: Medium"
## [1] "Medium"
## [1] "Car: Merc 450SE -Horsepower Category: Medium"
## [1] "Medium"
## [1] "Car: Merc 450SL -Horsepower Category: Medium"
## [1] "Medium"
## [1] "Car: Merc 450SLC -Horsepower Category: Medium"
## [1] "High"
## [1] "Car: Cadillac Fleetwood -Horsepower Category: High"
## [1] "High"
## [1] "Car: Lincoln Continental -Horsepower Category: High"
## [1] "High"
## [1] "Car: Chrysler Imperial -Horsepower Category: High"
## [1] "Low"
## [1] "Car: Fiat 128 -Horsepower Category: Low"
## [1] "Low"
## [1] "Car: Honda Civic -Horsepower Category: Low"
## [1] "Low"
## [1] "Car: Toyota Corolla -Horsepower Category: Low"
## [1] "Low"
## [1] "Car: Toyota Corona -Horsepower Category: Low"
## [1] "Medium"
## [1] "Car: Dodge Challenger -Horsepower Category: Medium"
## [1] "Medium"
## [1] "Car: AMC Javelin -Horsepower Category: Medium"
## [1] "High"
## [1] "Car: Camaro Z28 -Horsepower Category: High"
## [1] "Medium"
## [1] "Car: Pontiac Firebird -Horsepower Category: Medium"
## [1] "Low"
## [1] "Car: Fiat X1-9 -Horsepower Category: Low"
## [1] "Low"
## [1] "Car: Porsche 914-2 -Horsepower Category: Low"
## [1] "Medium"
## [1] "Car: Lotus Europa -Horsepower Category: Medium"
## [1] "High"
## [1] "Car: Ford Pantera L -Horsepower Category: High"
## [1] "Medium"
## [1] "Car: Ferrari Dino -Horsepower Category: Medium"
## [1] "High"
## [1] "Car: Maserati Bora -Horsepower Category: High"
## [1] "Medium"
## [1] "Car: Volvo 142E -Horsepower Category: Medium"