RCDS - Introduction to C++

Dr. Jesús Urtasun Elizari

Imperial College London - 2024 / 2025

Find the content of the course in GitHub:

https://github.com/ImperialCollegeLondon/RCDS-intro-cpp

Getting C++ set up on your own machine

Instructions are in the appendix.

Roadmap of the course

Chapter 1

• Introduction to Linux operative systems, terminal and bash.
• Programing languages and performance comparison. Text editors.
• First steps with C++. Hello world.

Chapter 2

• Variable types in C++, input / output statements.
• Basic mathematical operations.
• Compiling in parallel. Makefile.

Chapter 3

• Conditional statements if / else.
• Loops for, while, do while.
• Data file manipulation. Reading and writing files.

Chapter 4

• Arrays and vectors. Basic algebra.
• Functions in C++.
• Compiling functions and header files.

Chapter 5

• Pointers and memory allocation.
• Classes and OOP.
• Basic statistics. Computing momenta of a distribution.

Chapter 6

• Real algebra: scalar product, matrix-vector product
• Armadillo library
• Real RCDS problems: Rectilinear movement, estimate Higgs mass, numerical integration.

Appendix

A1. Getting C++ set up on your own machine

Follow the instructions below, depending on which type of machine you will use.

Step 1: Have a text editor ready

We are going to be writing our code in a text editor. This is a program which lets us produce plain text files. There are lots of choices available, but we recommend downloading VSCode.

Step 2: Have a C++ compiler installed and working

A compiler is a program which takes the text file we have written and turns it into something we can run. Compilers do not look like normal programs, with windows and graphics. Instead they are run using the command line. We will discuss this in class but for now, follow the instructions below, depending on which type of machine you will use.

Instructions for Mac and Linux

A C++ compiler should be installed by default on macOS and most Linux distributions.

1. Open Terminal.
2. Type c++ and press Enter.
3. If it says clang: error: no input files or c++: fatal error: no input files, then you are ready to go.
4. For Mac, if you don't see either of the error messages in 3. run xcode-select --install in terminal and try again.

Instructions for Windows (your own computer)

First let's check that you haven't already got a C++ compiler on your computer. If you have installed Fortran in the past, you might already have a C++ compiler.

1. Open Command Prompt from the Start menu (right-click the Start button and select Command Prompt).
2. Type g++ and press Enter.
3. If you get the error g++: fatal error: no input files, then you are good to go. If you get a different message, you don't have a C++ compiler installed and should continue following these instructions.
4. To install the compiler, follow the instructions on this YouTube video. Alternitavely you can install the windows subsystem for linux (WSL) and install a linux distribution from the Microsoft store. This is a bit more complicated and larger but will give you a linux environment on your windows machine with a C++ compiler pre-installed (I will be using WSL2 Ubuntu throughout the course). Is this awkward? Yes. Is it worth it? Yes!
5. Check that it works by following steps 1--3 above.

A2. YouTube videos for distance learning

Timestamps are in the descriptions and correspond to the numbering in this document. Content in the videos may differ slightly.

• Part 0: Pre-course instructions
• Part 1. You must have C++ set up on your machine before starting.
• Part 2
• Part 3
• Playlist

Licence

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International Licence.