#cp -r /public/teach/4A2/2019_4A2 .
#cd 2019_4A2
 
This directory contains all F90 Fortran source files of the skeleton
code for 4A2 : "euler.f90" is the main program, each of the other files
contains one subroutine. The directory also contains the geometry and 
flow condition data for 6 test cases (test*_geom and test*_flow). 

You need supply the correct lines in the .f90 files where are indicated 
by "INSERT your code here" to complete a workable code. The detailed
instructions on how to do this are given in "4A2EulerExercise2019.pdf"
(download on moodle the item "4A2 Write an Euler Solver"). Item 
"Writing the Basic Solver" (Write the Basic Solver.pdf) in Lecture 
Slides (2019) (on moodle) is also helpful.  Useful materials of 
Fortran 90 can be found in "fortran90.pdf" (on moodle item 
"Fortran Guide - Queens Belfast").

1) The compilation of the code is managed by the file "Makefile". Type 

   make

the operator system will compile all the *.f90 files into .o files and 
link the .o files into an executable "Euler". 

"make" is a command of the Unix system which uses the information in
"Makefile" to manage the compilation of executables. 
There are many benefits of using "Makefile". One is the following:
the system only re-compiles  the newly updated .f90 files (compared 
to the relevant .o files), that is, if a .f90 file is older than its .o
file, the system will do nothing. This is extremely efficient when managing 
big computer softwares. It is good that you learn how to use it now. 
You may like to have a look at the file "Makefile".

2) To run the code, type

  ./Euler