void TransformerSPRINGEMBEDDER::SpringEmbed(Graph& G, vector<float> dimension_limits, IntermediateStepHandler* intermediatestephandler)
{
vector<VectorND> tractions;
int dimensions = dimension_limits.size();
unstressed_spring_length = dimension_limits[0];
for(int i = 1; i < dimensions; i++)
unstressed_spring_length *= dimension_limits[i];
unstressed_spring_length /= G.NumberOfVertices();
unstressed_spring_length = pow(unstressed_spring_length, 1.0f/dimensions) / (dimensions * 2);
// init
srand ( time(NULL) );
for(VertexIterator a = G.BeginVertices(); a != G.EndVertices(); a++)
{
Coordinates coordinates;
for(int i = 0; i < dimensions; i++)
coordinates.push_back(fmod(rand(), dimension_limits[i]));
(*a)->SetCoordinates(coordinates);
// should make sure that no two vertices have the same position
tractions.push_back(VectorND(dimensions));
}
float max_movement;
iteration = 0;
do
{
// compute movement
max_movement = 0;
int i = 0;
for(VertexIterator a = G.BeginVertices(); a != G.EndVertices(); a++, i++)
{
VectorND traction = tractions[i] * friction;
// compute forces on a by the other vertices
VectorND aCoordinates((*a)->GetCoordinates(0));
for(VertexIterator b = G.BeginVertices(); b != G.EndVertices(); b++)
{
if(b==a)
continue;
// force on a by vertex b
VectorND bCoordinates((*b)->GetCoordinates(0));
traction += coulomb(aCoordinates, bCoordinates);
if((*a)->Adjacent(*b))
traction += hooke(aCoordinates, bCoordinates);
}
tractions[i] = traction;
}
// execute movement
VertexIterator a = G.BeginVertices();
for(int i = 0; a != G.EndVertices(); a++, i++)
{
Coordinates OldCoordinates = (*a)->GetCoordinates(0);
Coordinates NewCoordinates(dimensions);
for(int j = 0; j < dimensions; j++)
NewCoordinates[j] = max(0.0f,min(dimension_limits[j], OldCoordinates[j] + delta * tractions[i][j] ));
(*a)->SetCoordinates( NewCoordinates );
// for the loop-condition
float current_movement = 0.0f;
for(int j = 0; j < dimensions; j++)
current_movement += (OldCoordinates[j] - NewCoordinates[j]) * (OldCoordinates[j] - NewCoordinates[j]);
if(sqrt(current_movement) > max_movement)
max_movement = sqrt(current_movement);
}
if(intermediatestephandler != NULL)
intermediatestephandler->Handle(&G);
if(++iteration > nextincrease)
{
movement_threshold += 0.01f;
nextincrease *= 4;
}
if(iteration > max_iterations)
break;
}
while(max_movement > movement_threshold*unstressed_spring_length);
}
void ExportFilterRGML::Export(Graph& G, ostream& os, VertexColoring& vertexcoloring,
EdgeColoring& edgecoloring, float dpi, float edgewidth, float vertexradius)
{
StringTranslatorXML Translator;
os << "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
os << "<!-- www.Open-Graphtheory.org -->\n\n";
os << "<rdf:RDF\n"
<< " xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"\n"
<< " xmlns=\"http://purl.org/puninj/2001/05/rgml-schema#\"\n"
<< " xmlns:rgml=\"http://purl.org/puninj/2001/05/rgml-schema#\"\n"
<< ">\n\n";
os << " <Graph rdf:ID=\"graph\" rgml:directed=\"false\">\n";
/// declare vertices
os << " <nodes>\n";
os << " <rdf:Bag>\n";
for(VertexIterator v = G.BeginVertices(); v != G.EndVertices(); v++)
os << " <rdf:li rdf:resource=\"#n" << (*v)->GetID() << "\"/>\n";
os << " </rdf:Bag>\n";
os << " </nodes>\n\n";
/// declare edges and arcs
os << " <edges>\n";
os << " <rdf:Bag>\n";
for(EdgeIterator e = G.BeginEdges(); e != G.EndEdges(); e++)
os << " <rdf:li rdf:resource=\"#e" << (*e)->GetID() << "\"/>\n";
os << " </rdf:Bag>\n";
os << " </edges>\n";
os << " </Graph>\n\n";
/// write vertices
for(VertexIterator v = G.BeginVertices(); v != G.EndVertices(); v++)
os << " <Node rdf:ID=\"n" << (*v)->GetID() << "\" rgml:label=\"" << Translator.Translate((*v)->GetLabel()) << "\"/>\n";
/// write edges
for(EdgeIterator ei = G.BeginEdges(); ei != G.EndEdges(); ei++)
{
Edge* e = *ei;
if(e->IsHyperedge())
continue;
os << "\n <Edge rdf:ID=\"e" << e->GetID() << "\" directed=\"" << (e->IsEdge()?"false":"true") << "\""
<< " rgml:label=\"" << Translator.Translate(e->GetLabel()) << "\">\n";
os << " <source rdf:resource=\"#n" << e->From()->GetID() << "\"/>\n";
os << " <target rdf:resource=\"#n" << e->To()->GetID() << "\"/>\n";
os << " </Edge>\n";
}
/// write hyperedges
for(EdgeIterator ei = G.BeginEdges(); ei != G.EndEdges(); ei++)
{
Edge *e = *ei;
if(!e->IsHyperedge())
continue;
os << "\n <Edge rdf:ID=\"e" << e->GetID() << "\""
<< " rgml:label=\"" << Translator.Translate(e->GetLabel()) << "\">\n";
os << " <nodes>\n";
os << " <rdf:Seq>\n";
for(VertexEdgeConnectionIterator conn = e->BeginConnections(); conn != e->EndConnections(); conn++)
os << " <rdf:li rdf:resource=\"#n" << (*conn)->GetVertex()->GetID() << "\"/>\n";
os << " </rdf:Seq>\n";
os << " </nodes>\n";
os << " </Edge>\n";
}
os << "\n</rdf:RDF>\n";
}