Sample R lesson

Challenge 1

How can we make our lessons a bit more interactive??

Here’s some markdown code showing how to use markdown to do cool things in our quarto markdowns.


::: callout-tip
## Challenge 1
How can we make our lessons a bit more interactive??
:::

::: {.callout-caution collapse="true"}
## Solution

We can take advantage of cool markdown!

:::

You can define sections in your quarto using html.

<div class="questions">
</div>

Questions

  • What can R do?
  • How do I do it?

Objectives

  • Learn the basic R commands
# if using VSCode may been
#install.packages("languageserver")
hist(mtcars$mpg)

Challenge

Write a function to convert map scale. For example, on a 1:25,000 map (good for hiking!) the distance between two points is 15 cm. How far apart are these in real life? (3750 m).

[Reminder: 15 cm * 25000 = 375000 cm = 3750 m]

Your function should take as input two numbers: the distance on the map (in cm) and the second number of the scale and, i.e. calculate_distance(15, 25000) should return 375000

Solution 
#Declare the name of the function
# this is not a R example - but you get the idea!
def calculate_distance(distance_cm,scale):
    '''calculates distance based on map and scale
    returns: z
    inputs: distance_cm,scale
    distance_cm and scale are two integers
    returns the product of distance_cm and scale
    '''  
    
    return(distance_cm * scale)

Key points

  • You can store things in R in variables
  • Lists can be used to store objects of different types
  • Loops with for can be used to iterate over each object in a list
  • Functions are used to write (and debug) repetitive code once
  • Indexing

All materials copyright Sydney Informatics Hub, University of Sydney