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#include "GraphAutoLayout.h"
//#include "ImportForm.h"
GraphAutoLayout::GraphAutoLayout() {}
GraphAutoLayout::~GraphAutoLayout() {}
GraphAutoLayout::GraphAutoLayout(std::vector<ParseMatpower::BusData*> busData,
std::vector<ParseMatpower::BranchData*> branchData)
{
m_busData = busData;
m_branchData = branchData;
for(auto it = m_busData.begin(); it != m_busData.end(); ++it) {
GraphLayoutNode node;
m_nodes.push_back(node);
}
for(auto it = m_branchData.begin(); it != m_branchData.end(); ++it) {
ParseMatpower::BranchData* branch = *it;
float weight = 1.0;
if(branch->tap > 1e-3) weight = 2.0;
AddLink(branch->busConnections.first - 1, branch->busConnections.second - 1, weight);
}
}
void GraphAutoLayout::AddLink(size_t index1, size_t index2, float weight)
{
// If the two indices are the same, or if the weight is zero, do nothing (no link)
if(index1 == index2 || weight == 0.f) { return; }
// If the number of nodes is lesser than one of the indices, extend the nodes vector
size_t maxIndex = std::max(index1, index2);
size_t nodesMaxIndex = m_nodes.size() - 1;
for(size_t i = nodesMaxIndex; i < maxIndex; i++) {
GraphLayoutNode node;
m_nodes.push_back(node);
}
// Add an edge
m_edges.push_back({.node1 = m_nodes[index1], .node2 = m_nodes[index2], .weight = weight});
}
void GraphAutoLayout::Compute(size_t iterations)
{
wxProgressDialog pbd(_("Importing..."), _("Initializing..."), iterations, NULL,
wxPD_APP_MODAL | wxPD_AUTO_HIDE | wxPD_CAN_ABORT | wxPD_SMOOTH);
float nodesCount = m_nodes.size();
// Initialize nodes positions on a circle
float a = 0.f;
float da = 2.f * M_PI / nodesCount;
for(auto node = m_nodes.begin(); node != m_nodes.end(); node++) {
node->position.x = nodesCount * std::cos(a);
node->position.y = nodesCount * std::sin(a);
a += da;
}
// Initial parameters; other values can be chosen for area;
float area = nodesCount;
float k2 = area / nodesCount;
float k = sqrt(k2);
for(size_t i = 0; i < iterations; i++) {
// Temperature cools down; starts at 1, ends at 0
// (other formulas can be used for the cooling)
float temperature = 1.f - i / (float)iterations;
temperature *= temperature;
// Calculate repulsive forces
for(auto node1 = m_nodes.begin(); node1 != m_nodes.end(); node1++) {
node1->displacement = {0.f, 0.f};
for(auto node2 = m_nodes.begin(); node2 != m_nodes.end(); node2++) {
float dx = node1->position.x - node2->position.x;
float dy = node1->position.y - node2->position.y;
if(dx && dy) {
float d2 = dx * dx + dy * dy;
float coefficient = k2 / d2;
node1->displacement.x += coefficient * dx;
node1->displacement.y += coefficient * dy;
}
}
}
// Calculate attractive forces
for(auto edge = m_edges.begin(); edge != m_edges.end(); edge++) {
float dx = edge->node1.position.x - edge->node2.position.x;
float dy = edge->node1.position.y - edge->node2.position.y;
float d2 = dx * dx + dy * dy;
float coefficient = sqrt(d2) / k * edge->weight;
edge->node1.displacement.x -= dx * coefficient;
edge->node1.displacement.y -= dy * coefficient;
edge->node2.displacement.x += dx * coefficient;
edge->node2.displacement.y += dy * coefficient;
}
// Calculate positions
float sum = 0.f;
for(auto node = m_nodes.begin(); node != m_nodes.end(); node++) {
float d2 = node->displacement.x * node->displacement.x + node->displacement.y * node->displacement.y;
float d = sqrt(d2);
if(d > temperature) {
float coefficient = temperature / d;
node->displacement.x *= coefficient;
node->displacement.y *= coefficient;
sum += temperature;
} else {
sum += d;
}
node->position.x += node->displacement.x;
node->position.y += node->displacement.y;
}
if(!pbd.Update(i, wxString::Format("Iteration = %d", i))) {
pbd.Update(iterations);
i = iterations;
}
}
}
void GraphAutoLayout::CalculatePositions(int iterations, double scale)
{
Compute(iterations);
int index = 0;
for(auto it = m_busData.begin(); it != m_busData.end(); ++it) {
(*it)->busPosition = wxPoint2DDouble(m_nodes[index].position.x * scale, m_nodes[index].position.y * scale);
index++;
}
}
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