Week 2

Week 2 – Programming Basics: Loops, Conditionals, Functions

Learning Outcomes By the end of this week, students will be able to:

1. Use if/else statements.
2. Write for and while loops.
3. Create MATLAB functions.
4. Debug and profile MATLAB code.
5. Understand good coding practices for reproducibility.

Suggested Readings

• Frain, MATLAB for Economics and Econometrics, Ch. 4 (Programming structures), Ch. 7 (Functions).
• MatlabCheatSheet.pdf - Loops section.
• TutorialMatlab.pdf – Sections 5–7 (loops, functions, debugging).

In-Class Activities

• Write a loop to compute the first 10 Fibonacci numbers.
• Implement a function compound_interest(P, r, n) that calculates final capital.
• Add an if statement to handle invalid inputs.
• Use MATLAB’s debugging tools: breakpoints, dbstop if error.
• Time a loop vs. vectorized code with tic/toc.

Homework / Practice

• Create a function that simulates GDP growth over T periods given an initial GDP, growth rate, and random shocks.
• Write a script that:
  • Simulates 100 GDP paths.
  • Calculates mean and variance of final GDP.
  • Plots histogram of results.
• Document your code with comments and save outputs to a figure file.

Files

• Slides Week 2 – Slides from lecture.
• week2.m – Example script from lecture.
• week2_debug.m – Example debug script from lecture.
• compound_interest.m – Example function from lecture.
• gdp_simulate_starter.m – Starter function file for in class challenge.
• week2_challenge_starter.m – Starter file for in class challenge.
• week2_homework_starter.m – Starter file for homework.