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Climate Change Assignments - Fall, 2024

Lesson 2: Intermediate Operations

Estimated time to complete: 45 minutes
In this lesson, you will build upon the basics to create working scripts and functions and perform some analyses. By the end of this lesson, you will have created two of your required deliverables:

  • Your modified version of my_lucky_numbers.m
  • The figure my_lucky_numbers.png that you will create during your analyses

Video

Direct link to video.

1. Setup

  1. Make sure your Working Directory is set to / > MATLAB Drive > iSci3A12-SciProgramming. This is where we will run our scripts and analyses.
  2. In MATLAB, open the following files in the Editor window:
    • The script iSci_Intermediate.m, and
    • The function iSci_lucky_numbers.m

2. Edit and save a new function

  1. Save a copy of iSci_lucky_numbers.m in the same direcotory and name it my_lucky_numbers.m:
    • With iSci_lucky_numbers open, click Save > Save As...
      Save As Dialog Box
    • Name the new file my_lucky_numbers.m
  2. In the function declaration (the top line) in my_lucky_numbers.m, change the function name from iSci_lucky_numbers to my_lucky_numbers. Save your changes.
    • NOTE: When you call a function, it will execute the last saved version of the file. As a result, you need to save your changes to a function before it will be reflected in the output.

3. Completing the lesson

3.1 Understand my_lucky_numbers

  1. Read through the code and comments in my_lucky_numbers. You don’t need to understand every command, but try to get a sense of the logic behind the function.
  2. Using the usage example provided, run the function a few times to understand its output.
  3. Edit your my_lucky_numbers function so that instead of returning numbers between 1 and 49, it returns numbers between 1 and 100.
    • HINT: Find the value 49 in the code and replace it with 100.
    • Save your changes.

3.2 The scenario

You’ve been given a “lucky number generating program” from a friend (called my_lucky_numbers). You suspect that it’s outputting nothing but uniformly random numbers between 1 and 100. How can you investigate this?

3.3 The analysis

IMPORTANT NOTE: For this lesson, you will work through the exercises within the script iSci_Intermediate.m. The instructions are embedded as comments in the script, and you can run through the steps by highlighting line(s) and executing them in the Command Window with the F9 key (Windows) or Fn+Shift+F7 (Mac).

4. Deliverables

  • Ensure that your figure lucky_random_numbers.png has been created using all of the formatting commands included at the end of Intermeidate.m (you don’t need to add anything else beyond what exists in the script), and looks similar to the image that Jay showed in the final video. You’ll download this from MATLAB Drive in order to submit.
  • Ensure that all changes to your function my_lucky_numbers.m is saved.

5. Head to the next exercise

Once you’re done here, head to the next lesson to write your own function.