1 Preface 2 Linux as operating system, C++ as programming lan ...

1 PrefaceWe expect you, as students attending to the course “Introduction to Computational Physics”,to have already some, at least basic, knowledge about computers and computer programmingand experience working with a programming language like C++, Java, Fortran and tool likeMatlab, Maple, Mathematica, etc.While any familiarity with such languages and tools is highly favorable and makes is mucheasier for you to keep pace with this course with lesser amount of time and afford, being anabsolute beginner will not disqualify you from taking the course. In this case, however, you willneed more time and dedication to get the most out of the lessens and exercises. We will do ourbest to help you establish a solid and comprehensive background in this field which you willbe able in the future to further develop and of which you will have benefits for the rest of yourcareer.2 Linux as operating system, C++ as programming languageWe, generally, regard Linux as the most convenient operating system and C++ as the mostsuitable programming language under which we will develop our programs and simulations.The reason is to have a uniform working environment and to avoid diversity facilitating an easyand fast interaction between the students. However, everyone is free to choose his/her operatingsystemandprogramminglanguage,aslongasthegoalofthelessonsandtheexercisesisreached.In the following sections, we will help you writing simple programs in C++ and run them underLinux and assign you with simple tasks introducing you to the subject.3 Logging in and getting things to work• The computers are double boot machines, i.e. you may have to restart for Linux. Log inwith your account information.• Open a browser. Under the following address you can find all the information and scriptsabout this course: http://www.ifb.ethz.ch/education/IntroductionComPhys• Open a terminal (shell). A shell is a program that provides the traditional, text-onlyuser interface for Linux and other Unix-like operating systems. Its primary function isto read commands that are typed into a console (i.e., an all-text display mode) or terminalwindow (an all-text window) and then execute (i.e., run) them. (Definition fromhttp://www.linfo.org)• Create a new directory named, e.g. test: mkdir test• Enter the created directory: cd test• Start an editor (here, e.g. gedit) to write a program in C++: gedit Hello.cc (Alwaysuse reasonable names telling a little bit about the content.)• Write whatever you like, save and exit the editor.

4 Some useful commandsCOMMAND USAGEpwd shows the path of the current directorymkdir name creates directory name“ ”cd name change to directory name“ ”gedit starts GNU-Editor (recommended)(x)emacs Starts (X)EMACS editorls lists files and directoriesls -l also display more information, as sizecp, mv copy, move files and directoriesman displays the documentation to a commandg++ compiles C, C++ programscommand & command into backgroundexit exit shell/window5 Our first programm• Create a new directory (subdirectory) for the exercises, e.g., comphys.• Copy our little program hello.cc into this directory: cp hello.cc comphys/• Change into comphys: cd comphys• Open the editor to edit hello.cc. Write the following code and save it:#include using namespace std;int main(){cout

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