Scientific Programming with C++

In this module SCPROG the exercises and projects will be submitted online into a version control system Git hosted at the MatNat GitLab platform, which is a web-based Git repository manager similar to GitHub and Bitbucket.

Handing in solutions to exercises and projects digitally on such a platform is a good way of learning and training collaborative coding, which is commonplace in Scientific Computing research groups.

In order to allow fast correction and evaluation of submitted solutions, we require a predefined structure of the repositories and coding styles to be follwed. Not following these rules for repositories may result in your solution not being reviewed. You will then have to reformat it and submit again. Not following the style guidelines may result in point deduction, with the amount of points depending on the impact your style could have on actual collaborative projects.

Your Repository on GitLab

Account

In the first tutorial we will create an account on the local GitLab platform, using the ZIH-Login (s...-number) for the account user name associated to your TU-Dresden email address. This ensures that you will get credit for your submissions.

Project Name

Please form groups of up to three members and exchange contact details so you can find each other on GitLab. One of you should create a private (!) project, and invite the rest of the group. The name of your project is scprog-Name1Name2Name3, where Name1 is the last name of the first student, Name2 that of the second student, and so on. These names should be sorted alphabetically. If your lineup changes for any reason during the course of the semester, please create a new project that reflects this and inform your tutors.

Directory Structure

Your repository should consist of two levels of directories, one for the exercise sheets and one for the individual exercises. This results in a tree structure like this:

sheet1
 +-- exercise1
 |    +-- main.cc
 |    +-- solution.txt
 |    \-- <header and source files>
 |
 +-- exercise2
 |    \-- <files as above>
 |
 \-- (...)

sheet2
 +-- exercise1
 +-- exercise2
 \-- (...)

(...)

You are free to name and structure your C++ files in any way you like, but there should always be a file named main.cc that is a sample application of your implemented classes. Often the content is given in the exercise, if it isn’t you are free to choose sensible test cases yourselves. Make sure that this file main.cc can be compiled with the command given in the lecture, or alternatively provide a MakeFile or CMakeLists.txt that builds the exercise.

The file solution.txt is meant for the output of your main.cc and for answering questions that appear in the exercises. If an exercise is of theoretical nature and doesn’t include actual coding, this is the only file you have to submit. Optionally you can submit a Markdown file solution.md instead. This allows basic formatting of the text.

Access to the Repository

Please give your tutor @spraetor write access to your project so that your submissions can be graded. You also need to give read access to the repository to all tutors if there is more than one, regardless of the group you are in. This allows for flexible handling of unforeseen situations.

Submission of Exercises

On each exercise sheet some exercises are marked for submission. You have approximately two weeks for each of these exercises, where the final date is written next to the exercise. In order to get your solutions reviewed, it has to be committed to your GitLab repository following the procedure:

1. For each exercise sheet create a new branch called sheetX where X is the number of the sheet.
2. Create the new directory following the directory structure as above
3. Commit your solutions to the branch
4. Create a merge request to your master branch

After final review of your submission (and maybe inclusion of your corrections) you get a 👍 and can merge your branch into your master branch.

Note: each member of the group should participate in the submission, i.e. commit her/his contributions individually and not just by the creator of the repository, if the exercise amount allows for splitting.

Style Guidelines

All programs you submit should follow basic programming rules like the following:

• Formatting
  • Put each instruction on a separate line (two lines if it is very large)
  • Use spaces to separate variable names, functions and operators
  • Indent your lines to visually mark different lines belonging to different scopes
• Variable names
  • The name should reflect the purpose of the variable
  • Variable names start with a lowercase letter, types with an uppercase letter
  • The rest of the name format for identifiers is up to you
  • Simple counting integers and similar variables are exempt
• Comments
  • Comments allow others to understand your intentions
  • Tutors can only give you points if they understand what you were trying to do
  • Guideline: one comment per class, per function, per algorithm subtask, per tricky or "exotic" source line
  • Don’t comment to much either, this may visually drown the actual code or diverge from what is actually coded (!)
  • Leave out trivial comments ("This is the constructor")
• Language constructs
  • You may use any construct you want, even if it has not yet been introduced in the lecture
  • Avoid constructs that have been superseded by better alternatives in the lecture
  • Declare variables and references as const where it is possible
  • Separate interface and implementation by correctly using public and private
  • Use exceptions instead of asserts / aborts and smart pointers instead of raw pointers once the lecture has introduced them

See Google C++ Style Guide for more rules and guidelines on the coding style. Also, see the C++ Core Guidelines for a comprehensive list of best practice programming rules for C++.

More reading

Online references and literature useful for completing the exercises are listed below:

• Online-References:
  • cppreference.com, BLAS, LAPACK, DUNE, Git, Boost, CMake
• Cheetsheets:
  • Divhints, Git, Linux Command Line
• Tutorials:
  • MTL4, Git
• Compiler:
  • GCC, Clang, Intel Icc
• Books:
  • Discovering Modern C++: An Intensive Course for Scientists, Engineers, and Programmers, Peter Gottschling, 2015: slub, online
  • References: Die C++ Programmiersprache (Bjarne Stroustrup), C++ Kurz & Gut (Kyle Loudon, Rainer Grimm): slub
  • Beginners: C++ Primer (Stanley Lippman, Josee Lajoie, Barbara E. Moo): online
  • Intermediate level: Effective Modern C++ (Scott Meyers): slub, online, C++ Templates: The Complete Guide (David Vandevoorde, Nicolai M. Josuttis): online
  • Experts: Modern C++ Design (Andrei Alexandrescu): online, C++ Template Metaprogramming (David Abrahams, Aleksey Gurovoy): online