findFAS

===============================================================================

 Title:        findFAS
                                                             
 Project:      Transformation of HYSDEL model into PWA model

 Purpose:      find feedback arc set (FAS)

 Input:        A: adjacency matrix

 Output:       FAS: feedback arc set: FAS(i,:) contains the i-th feedback arc 
                    from vertex FAS(i,1) to vertex FAS(i,2)
               s_fas: vertex sequence corresponding to A_fas (the i-th entry of 
                      s_fas contains the number of the i-th vertex and 
                      corresponds to the i-th row and column of A, the 
                      vertexTable maps the numbers of the vertices to their 
                      variable names)

 Comments:     The algorithm is based on 
               'A fast and effective heuristic for the feedback arc set problem', 
               P. Eades, X. Lin, W.F. Smyth, 
               Information Processing Letters 47 (1993) 319-323

 Authors:      Tobias Geyer <geyer@control.ee.ethz.ch>