From: Francois Fleuret Date: Fri, 24 Aug 2012 02:44:27 +0000 (+0200) Subject: Cosmetics. X-Git-Url: https://fleuret.org/cgi-bin/gitweb/gitweb.cgi?a=commitdiff_plain;h=7704ecb19140055b21e1012cd0d394f2a6db98eb;p=mtp.git Cosmetics. --- diff --git a/mtp_graph.cc b/mtp_graph.cc index a60e532..4d142cd 100644 --- a/mtp_graph.cc +++ b/mtp_graph.cc @@ -41,7 +41,7 @@ public: int id; Edge *leaving_edges; scalar_t distance_from_source; - Edge *best_pred_edge_to_source; + Edge *pred_edge_toward_source; int iteration; // Used in find_shortest_path to know if we already // added this vertex to the front @@ -163,20 +163,6 @@ void MTPGraph::print_dot(ostream *os) { ////////////////////////////////////////////////////////////////////// -void MTPGraph::initialize_positivized_lengths_with_min() { - scalar_t length_min = 0; - for(int n = 0; n < _nb_vertices; n++) { - for(Edge *e = _vertices[n].leaving_edges; e; e = e->next_leaving_edge) { - length_min = min(e->length, length_min); - } - } - for(int n = 0; n < _nb_vertices; n++) { - for(Edge *e = _vertices[n].leaving_edges; e; e = e->next_leaving_edge) { - e->positivized_length = e->length - length_min; - } - } -} - void MTPGraph::update_positivized_lengths() { for(int k = 0; k < _nb_edges; k++) { Edge *e = _edges + k; @@ -195,7 +181,7 @@ void MTPGraph::force_positivized_lengths() { if(e->positivized_length < 0) { #ifdef VERBOSE residual_error -= e->positivized_length; - max_error = max(max_error, fabs(e->positivized_length)); + max_error = max(max_error, - e->positivized_length); #endif e->positivized_length = 0.0; } @@ -207,8 +193,8 @@ void MTPGraph::force_positivized_lengths() { } // This method does not change the edge occupation. It update -// distance_from_source and best_pred_edge_to_source. -void MTPGraph::find_shortest_path(Vertex **_front, Vertex **_new_front) { +// distance_from_source and pred_edge_toward_source. +void MTPGraph::find_shortest_path() { Vertex **tmp_front; int tmp_front_size; Vertex *v, *tv; @@ -217,7 +203,7 @@ void MTPGraph::find_shortest_path(Vertex **_front, Vertex **_new_front) { for(int v = 0; v < _nb_vertices; v++) { _vertices[v].distance_from_source = FLT_MAX; - _vertices[v].best_pred_edge_to_source = 0; + _vertices[v].pred_edge_toward_source = 0; _vertices[v].iteration = 0; } @@ -238,7 +224,7 @@ void MTPGraph::find_shortest_path(Vertex **_front, Vertex **_new_front) { tv = e->terminal_vertex; if(d < tv->distance_from_source) { tv->distance_from_source = d; - tv->best_pred_edge_to_source = e; + tv->pred_edge_toward_source = e; if(tv->iteration < iteration) { _new_front[_new_front_size++] = tv; tv->iteration = iteration; @@ -270,26 +256,23 @@ void MTPGraph::find_best_paths(scalar_t *lengths) { // We use one iteration of find_shortest_path simply to propagate // the distance to make all the edge lengths positive. - find_shortest_path(_front, _new_front); + find_shortest_path(); update_positivized_lengths(); - // #warning - // initialize_positivized_lengths_with_min(); - do { force_positivized_lengths(); - find_shortest_path(_front, _new_front); + find_shortest_path(); update_positivized_lengths(); total_length = 0.0; // Do we reach the _sink? - if(_sink->best_pred_edge_to_source) { + if(_sink->pred_edge_toward_source) { // If yes, compute the length of the best path v = _sink; - while(v->best_pred_edge_to_source) { - total_length += v->best_pred_edge_to_source->length; - v = v->best_pred_edge_to_source->origin_vertex; + while(v->pred_edge_toward_source) { + total_length += v->pred_edge_toward_source->length; + v = v->pred_edge_toward_source->origin_vertex; } // If that length is negative if(total_length < 0.0) { @@ -298,8 +281,8 @@ void MTPGraph::find_best_paths(scalar_t *lengths) { #endif // Invert all the edges along the best path v = _sink; - while(v->best_pred_edge_to_source) { - e = v->best_pred_edge_to_source; + while(v->pred_edge_toward_source) { + e = v->pred_edge_toward_source; v = e->origin_vertex; e->invert(); // This is the only place where we change the occupations of @@ -311,6 +294,8 @@ void MTPGraph::find_best_paths(scalar_t *lengths) { } while(total_length < 0.0); + // Put back the graph in its original state (i.e. invert edges which + // have been inverted in the process) for(int k = 0; k < _nb_edges; k++) { Edge *e = _edges + k; if(e->occupied) { e->invert(); } @@ -331,11 +316,11 @@ int MTPGraph::retrieve_one_path(Edge *e, int *nodes) { for(f = e->terminal_vertex->leaving_edges; f; f = f->next_leaving_edge) { if(f->occupied) { nb_choices++; next = f; } if(nb_choices == 0) { - cerr << "Non-sink path end point?!" << endl; + cerr << "retrieve_one_path: Non-sink end point." << endl; abort(); } if(nb_choices > 1) { - cerr << "Non node-disjoint path, can not retrieve." << endl; + cerr << "retrieve_one_path: Non node-disjoint paths." << endl; abort(); } } diff --git a/mtp_graph.h b/mtp_graph.h index 7ccbfe3..6b8c181 100644 --- a/mtp_graph.h +++ b/mtp_graph.h @@ -31,10 +31,11 @@ class Vertex; class Edge; class MTPGraph { - void initialize_positivized_lengths_with_min(); void update_positivized_lengths(); void force_positivized_lengths(); - void find_shortest_path(Vertex **front, Vertex **new_front); + void find_shortest_path(); + // Retrieve the path starting on edge e and return its length. If + // nodes is non-null, stores the node met along the path in it. int retrieve_one_path(Edge *e, int *nodes); Vertex **_front, **_new_front;