Making Function in R

Homepage for the Making Functions in R workshop hosted by the Brock University Digital Scholarship Lab

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Making Functions in R

In this workshop you will get begin developing in R to the point that you can start crafting the tools that you need for the projects that are important to you. This workshop will cover:

Estimated workshop length: 2 hours


Setup Instructions

In preparation for this workshop, you will need to have an R Studio Cloud account and have a new project open. Follow the steps below to get set up.

Source Button Location

Title Change


Helpful Information

Conditional Statement Symbols

Symbol Description
== Is equal to
!= Is not equal to
< Is less than
<= Is less than or equal to
> Is greater than
>= Is greater than or equal to

Format of “if” statement


if (CONDITIONAL-STATEMENT) {
    CODE-TO-EXECUTE
    } else if (CONDITIONAL-STATEMENT) {
    CODE-TO-EXECUTE
    } else {
    CODE-TO-EXECUTE
    }
  

Format of “for” loop

for (NEW-VARIABLE in VECTOR) {
    CODE-TO-EXECUTE
    }

Format of “while” loop

while (CONDITIONAL-STATEMENT) {
    CODE-TO-EXECUTE
}

Format of “repeat” loop

repeat {
    CODE-TO-EXECUTE  (REMEMBER TO INCLUDE A break() TO STOP THE LOOP)
}

Format of Timer

if (1==1){
  startTime <- Sys.time()
  
  YOUR CODE HERE
  
  endTime<- Sys.time()
  print(endTime - startTime)
}

Format for Function

FUNCTION-NAME <- function(ARGUMENT-VARIABLE-1, ARGUMENT-VARIABLE-2, ) {
return(OUTPUT-OF-FUNCTION)
}

Workshop Tasks

Task Set #1
A. Create a variable that contains a number
B. Create some code that assesses the number and returns one of the following statements:

C. Test out your code by redeclaring your variable with values that will get each result and then running your code again.
D. When you are done type “CODE COMPLETE!!” into the chat.

Task Set #2

A. Make a variable called numList that contains a list of 10 numbers of your choice using the c() function
B. Write a for loop that runs your code from the last set of questions on each number in the list.
C. Make a numLoops variable that has a value of 0
D. Make a numBig variable with a value over 100,000
E. Use a while loop to determine how many times you can subtract 14 from your number before it is smaller than 100
F. Make a variable called myNum with a value that is at least 6 digits long
G. Make a variable called loopGuess with a value of 0
H. Find out how long it would take for a repeat loop to go from 0 to your number
I. When you are done type “LOOPS MASTERED!!!” into the chat

Task Set #3

A. Make a variable called myList containing ten numbers between 50 and 150
B. Make a function that, when given the variable, will tell you how many of the numbers smaller than 100 and how many are equal to or greater than 100.
C. When you have finished type “GOT IT!!” in the chat
BONUS. Make it so that if there is the same amount of numbers below 100 as there are equal to or above, the result is displayed with “Perfect Balance!” at the end


Next Steps

If you are looking to continue enhancing your knowledge of R, check out our other R workshops or try out one of the options below!

YaRrr! The Pirate’s Guide to R

W3Schools R Tutorial


This workshop is brought to you by the Brock University Digital Scholarship Lab. For a listing of our upcoming workshops go to Experience BU if you are a Brock affiliate or Eventbrite page for external attendees.