Installing Xfoil on Fedora 12 Linux

These are the steps that I went through to build Xfoil using double point precision on Fedora 12.  I used the gcc and gfortran compilers, and if you choose to use different ones, then some of the compiler flags may be different.  Before trying to build Xfoil, run the command sudo yum groupinstall “Development Tools”.  Not everything downloaded from the development group is needed to install Xfoil.  Alternatively, you can try to individually install the certain packages that are needed just to build Xfoil.

To get started first download the source file from http://web.mit.edu/drela/Public/web/xfoil/.  Extract the source tar file, cd into the directory Xfoil, and then follow the steps below.

Step 1 – Build the Orrs-Summerfield Database

Use cd to switch into the Xfoil/orrs/ directory and then run pwd.  Copy the ouput from pwd, and then cd into the src/ directory.  Edit the file osmap.f and look for the line DATA OSFILE / ‘/var/local/codes/orrs/osmap.dat’ /.  Change this line to DATA OSFILE / ‘{Output from pwd}/osmap.dat’ /, where {Output from pwd} is what was just copied before.

Now run cd ../bin/ and edit the make file, MakeFile_DP.  Make the following changes to that file.

1. Change FC = f77 to FC = gfortran.
2. Change FLG = -O -r8 to FLG = -O -fdefault-real-8 -fdefault-double-8.
3. Look for the line #  Uncomment for Intel Fortran Compiler, and then comment out everything related to the Intel compiler.

Then run the following commands:

[brad@localhost ~]$ make -f Makefile_DP osgen
[brad@localhost ~]$ make -f Makefile_DP osmap.o
[brad@localhost ~]$ cd ..
[brad@localhost ~]$ bin/osgen osmaps_ns.lst

Step 2 – Build the Plot Library

Use the cd command to switch to the Xfoil/plotlib/ directory.  Open up the make file and then make the following changes.

1. Find the line PLTLIB=libPlt.a.  Comment out this line and uncomment the line below it, which should read PLTLIB = libPltDP.a.
2. Find the section Default compilers and flags, install commands, and change the default compilers by setting FC = gfortran and CC = gcc.
3. Find the line DP = -r8 and replace it with DP = -fdefault-real-8 -fdefault-double-8.  Make sure it is uncommented.
4. Comment out the line include ./config.make.

Save and close the make file, and then run the make from the terminal.

Step 3 – Make Programs in /bin

Now switch to the Xfoil/bin/ directory, and open up the make file.  Then make the following changes.

1. Set the BINDIR equal to /usr/local/bin (BINDIR = /usr/local/lib).
2. Find the line PLTOBJ = ../plotlib/libPlt.a and comment it out.
3. Find the line ###  Default compilers and flags.
4. Change FC = f77 to FC = gfortran.
5. Change CC = cc to CC = gcc.
6. Comment out the FFLAGS and FFLOPT variables.
7. Look for the line ### Intel Fortran Compiler, and then comment out the next few lines for this compiler.  They are not needed.
8. Find the line ###Double precision option.
9. Change FFLAGS  = -O -r8 -CB to FFLAGS  = -O -fbounds-check -fdefault-real-8 -fdefault-double-8.
10. Change FFLOPT  = -O -r8 -CB to FFLOPT  = -O fbounds-check -fdefault-real-8 -fdefault-double-8.
11. Comment out the second set of FFAGS and FFLOPT.  These variables only need to be set once.

If you try to compile at this point you will get most likely get the following error.

gfortran -c -O -fbounds-check -fdefault-real-8 -fdefault-double-8  ../src/xoper.f
../src/xoper.f:117.22:

IINPUT(I) = 2**31
1
Error: Arithmetic overflow at (1)
make: *** [xoper.o] Error 1

There are two errors in the source code that need to be fixed.  The first one is in the file pplot.f and the second one is in the file xoper.f.  Running the following commands should fix these problems.  Note that before running the sed commands you want to be in the Xfoil/src/ directory.

[brad@localhost Xfoil]$ cd src/
[brad@localhost src]$ sed -i ‘s/LOGICAL ERROR, LGETFN/LOGICAL ERROR, LGETFN, LERR/g’ pplot.f
[brad@localhost src]$ sed -i ‘s/IINPUT(I) = 2\*\*31/IINPUT(I) = HUGE(0)/g’ xoper.f

Then change back to the Xfoil/bin/ directory and run make.

[brad@localhost bin]$ make xfoil
[brad@localhost bin]$ make  pplot
[brad@localhost bin]$ make pxplot

After I compiled everything, the xfoil command was not moved into /usr/local/bin.  This can be done manually by running sudo cp xfoil /usr/local/bin/.