Force Algorithm with Complexity O(N): a users guide


CONTENTS

  1. Overview
  2. Guarantee
  3. Compiler options
  4. Installation
  5. Use of the code
  6. Some tips for using the code
  7. About bugs

  1. OVERVIEW

    The code falcON described here is not a N-body code, but merely a package for computing the accelerations (and some other things, too), which can be used as Poisson solver in your existing N-body code.

  2. GUARANTEE

    This package comes with absolutely no guarantee whatsoever! The unpacking, compiling, and using of the code is entirely at the risk of the user alone.
  3. COMPILER OPTIONS

    Before running make, you may want arrange for some non-default settings that control certain code features as follows.

  4. INSTALLATION

    The installation is best done with GNU make (the makefiles provided don't work for, e.g., Solaris make) and using the GNU gcc compiler. I used gcc version 2.95.2. I also tried version 3.0, but I only managed to produce larger and slower code (and compilation took longer). The making takes a little while but should not produce any warning or error messages. Otherwise something might be wrong. To generate a library, type "make falcON", which creates the library lib/libfalcON.a. A two-dimensional version (not tested) can be created by typing instead "make falcON2D", which creates the library lib/libfalcON2D.a.
  5. USE OF THE CODE

    As to the proper values of the various parameters (softening and tolerance parameter) you are strongly advised to carefully read the notes of caution .

  6. SOME TIPS ABOUT USING THE CODE

  7. ABOUT BUGS

    Each of the files falcON.h, falcON_C.h, and falcON.f, contains a little section about known bugs. If you think you found another bug, please send me a bug report. Thanks.

Have Fun!


Walter Dehnen
Last modified: Mon Jun 10 16:59:49 MET DST 2002