1. For and While Loops

Question 1.1: Write in words the difference between a `for` loop and a `while` loop.

ANSWER: YOUR ANSWER HERE

Question 1.2: Preallocate a matrix of NAs with 3 rows and 8 columns, called `double_matrix`. Manually specify the first column equal to the values 1, 2, and 3. Using a nested loop, fill in the matrix, row by row, such that each value is double that to its left.

For example, the first row of the matrix should be: 1, 2, 4, 8, 16, 32, 64, 128

# [YOUR CODE HERE]

Question 1.3: Ask ChatGPT the following question: “Write a while loop in R that samples the integers randomly between 1 and 100 until the number 50 is selected. Print how many iterations it took.” Then, display the code ChatGPT wrote, say if it worked or not, and describe the steps ChatGPT took to reach a solution! (If it does not run, change the chunk option to `eval=FALSE`). ChatGPT can be accessed at chat.openai.com.

# [ChatGPT's CODE HERE]

ANSWER: YOUR ANSWER HERE

Question 1.4: Write a while loop that keeps “flipping 5 coins” until you get 5 heads. Have the function count how many sets of 5 coin flips it took until getting 5 heads, and return that number.

Hint: You can flip 5 coins using the code rbinom(n=1,size=5,prob=.5). You have gotten 5 heads when the output is 5.

# [YOUR CODE HERE]

2. Functions

Question 2.1: Pick a built-in R function and describe its input(s) and output(s).

ANSWER: YOUR ANSWER HERE

Question 2.2: Write a function, called `doubler`, that takes a single number as its input and returns a vector of length 8. The vector should contain the initial value, doubled consecutive times. Be sure to check if a single number was given!

Hint: If input is 1, output should be c(1,2,4,8,16,32,64,128).

# [YOUR CODE HERE]

Question 2.3: Use `doubler` on the inputs 1, 2, and 3. Do you get the same values as in question 1.2? (You should!)

# [YOUR CODE HERE]

3. Apply

Question 3.1 Write an `apply()` statement to take the median value of each column in the `cars` dataset.

Hint: Use the median() function inside your apply() command!

# [YOUR CODE HERE]

Question 3.2 Using `ggplot`, make a scatterplot of the `speed` and `dist` variables in `cars`. Then, add an appropriate horizontal and vertical line symbolizing the median value of each variable.

Hint: Using the layers geom_vline(xintercept = ) and geom_hline(yintercept = )

# [YOUR CODE HERE]

Homework 7: Loops, Functions, and Apply

YOUR NAME

DATE

1. For and While Loops

Question 1.1: Write in words the difference between a `for` loop and a `while` loop.

Question 1.2: Preallocate a matrix of NAs with 3 rows and 8 columns, called `double_matrix`. Manually specify the first column equal to the values 1, 2, and 3. Using a nested loop, fill in the matrix, row by row, such that each value is double that to its left.

Question 1.4: Write a while loop that keeps “flipping 5 coins” until you get 5 heads. Have the function count how many sets of 5 coin flips it took until getting 5 heads, and return that number.

2. Functions

Question 2.1: Pick a built-in R function and describe its input(s) and output(s).

Question 2.2: Write a function, called `doubler`, that takes a single number as its input and returns a vector of length 8. The vector should contain the initial value, doubled consecutive times. Be sure to check if a single number was given!

Question 2.3: Use `doubler` on the inputs 1, 2, and 3. Do you get the same values as in question 1.2? (You should!)

3. Apply

Question 3.1 Write an `apply()` statement to take the median value of each column in the `cars` dataset.

Question 3.2 Using `ggplot`, make a scatterplot of the `speed` and `dist` variables in `cars`. Then, add an appropriate horizontal and vertical line symbolizing the median value of each variable.

Homework 7: Loops, Functions, and Apply

YOUR NAME

DATE

1. For and While Loops

Question 1.1: Write in words the difference between a for loop and a while loop.

Question 1.2: Preallocate a matrix of NAs with 3 rows and 8 columns, called double_matrix. Manually specify the first column equal to the values 1, 2, and 3. Using a nested loop, fill in the matrix, row by row, such that each value is double that to its left.

Question 1.4: Write a while loop that keeps “flipping 5 coins” until you get 5 heads. Have the function count how many sets of 5 coin flips it took until getting 5 heads, and return that number.

2. Functions

Question 2.1: Pick a built-in R function and describe its input(s) and output(s).

Question 2.2: Write a function, called doubler, that takes a single number as its input and returns a vector of length 8. The vector should contain the initial value, doubled consecutive times. Be sure to check if a single number was given!

Question 2.3: Use doubler on the inputs 1, 2, and 3. Do you get the same values as in question 1.2? (You should!)

3. Apply

Question 3.1 Write an apply() statement to take the median value of each column in the cars dataset.

Question 3.2 Using ggplot, make a scatterplot of the speed and dist variables in cars. Then, add an appropriate horizontal and vertical line symbolizing the median value of each variable.

Question 1.1: Write in words the difference between a `for` loop and a `while` loop.

Question 1.2: Preallocate a matrix of NAs with 3 rows and 8 columns, called `double_matrix`. Manually specify the first column equal to the values 1, 2, and 3. Using a nested loop, fill in the matrix, row by row, such that each value is double that to its left.

Question 2.2: Write a function, called `doubler`, that takes a single number as its input and returns a vector of length 8. The vector should contain the initial value, doubled consecutive times. Be sure to check if a single number was given!

Question 2.3: Use `doubler` on the inputs 1, 2, and 3. Do you get the same values as in question 1.2? (You should!)

Question 3.1 Write an `apply()` statement to take the median value of each column in the `cars` dataset.

Question 3.2 Using `ggplot`, make a scatterplot of the `speed` and `dist` variables in `cars`. Then, add an appropriate horizontal and vertical line symbolizing the median value of each variable.