Puzzle Activity: Writing Functions

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This activity will ask you to write several small functions, then use them to unscramble a message.

Many of the functions have been started for you below, but none of them are complete as-is.

1. Write a function called divide_and_round(), which takes a number or vector of numbers, divides them all by their smallest value, and rounds the results to the nearest whole number.

Test it by running the code below the function.

divide_and_round <- function(nums){
  
  my_min <- min(nums, na.rm = TRUE)
  divided <- nums/my_min
  
}


test <- c(1:5, NA)

divide_and_round(test)

2. Write a function called no_nines_or_twelves(), which takes a number or vector of numbers and returns TRUE if the number is NOT divisible by 9 or 12, FALSE otherwise.

no_nines_or_twelves <- function(nums){
  
  check <- !(nums %% 9 == 0 | nums %% 12 == 0)
  
}

test <- c(1:10*5, NA)

no_nines_or_twelves(test)

3. Write a function called every_other() which takes a vector and returns every other value in the vector. Accomplish this with a for loop. (Although there are certainly better ways to do it!)

Include an optional argument called “start” which lets you choose where to start skipping; that is, if start = 1, we return the 1st value, 3rd, 5th, etc. and if start = 2, we return the 2nd, 4th, 6th, etc.

every_other <- function(vec){
  
  if(start == 2){

    
  } else if(start == 1) {
    
    
    
    
  }
  
}

test <- c(1:10)

every_other(test)
every_other(test, start = 2)

4. Write a function called shorten() which takes a vector and keeps dropping the first value, until the sum of the vector is less than 350 Return the remaining values.

Hint: You probably want to either use the cumsum() function, or write a while() loop.

Be sure to test your function.

shorten <- function(){

  
}

5. Once you have written your four functions correctly, copy-pase and run the following code:

my_vec <- c(39, 1.87, 48, 11, 8, 45, 21, 5, 12, 33, 9, 11, 108, 4, 18, 5, 16, 17, 8, 48, 27, 24, 4, 22, 12, 27, 23, 46, 42, 35, 15, 34, 36, 26, 18, 10, 18.21, 72.04, 36.9, 41.81, 29, 89.75, 34.03, 20.18, 48.74, 15.76, 31.86, 83.6, 43.55, 39.99, 23.55, 8.54, 24.71, 22.02, 9.71, 62.14, 35.46, 16.61, 15.66, 21.29, 30.52, 201.07, 45.81, 7.85, 30.13, 34.14, 22.62, 10.2, 6.02, 30.12, 10.64, 31.72, 24.57, 14.43, 43.37, 89.93, 44.72, 51.32, 13.62, 45.56, 22.96, 7.05, 29.99, 41.38, 26.59, 23.04, 19.82, 50.73, 39.56, 43.79, 30.22, 85.85, 5.78, 78.85, 29.52, 66.27, 44.06, 27.28, 24.43, 64.32, 3.35, 67.45, 46.72, 48.44, 48.65, 33.3, 40.28, 19.04)

my_vec <- every_other(my_vec, start = 2)
my_vec <- divide_and_round(my_vec)
my_vec <- every_other(my_vec, start = 1)
my_vec <- shorten(my_vec)
my_vec <- my_vec[no_nines_or_twelves(my_vec)]

my_vec <- sort(my_vec)

my_vec

If you have done everything correctly, your final vector will be six numbers long. Google these six numbers to find a TV show as your final answer.