GraphGeneratorKIT / network_generator.py
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Create network_generator.py
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import networkx as nx
import random
from visualizer import get_sorted_nodes
def validate_topology(G, topology):
n = len(G.nodes())
e = len(G.edges())
if n < 3: return True, "Graph too small for strict validation."
avg_deg = (2.0 * e) / n
if topology == "highly_connected":
if avg_deg < 2.5:
return False, f"Graph is sparse (Avg Degree: {avg_deg:.1f}) for 'Highly Connected'. Add more target edges."
elif topology == "bottlenecks":
bridges = list(nx.bridges(G))
if len(bridges) == 0 and avg_deg > 3.0:
return False, "Graph lacks distinct bottleneck links (bridges) and is too dense. Reduce target edges."
elif topology == "linear":
max_deg = max([d for n, d in G.degree()]) if len(G.nodes()) > 0 else 0
if max_deg > 4 or avg_deg > 2.5:
return False, f"Graph contains hub nodes (Max Degree: {max_deg}) or is too dense for 'Linear'. Reduce edges."
return True, "Topology matches definition."
class NetworkGenerator:
def __init__(self, width=10, height=10, variant="F", topology="highly_connected",
node_drop_fraction=0.1, target_edges=0,
bottleneck_cluster_count=None, bottleneck_edges_per_link=1):
self.variant = variant.upper()
self.topology = topology.lower()
self.width = int(width)
self.height = int(height)
self.node_drop_fraction = float(node_drop_fraction)
self.target_edges = int(target_edges)
self.node_factor = 0.4
if bottleneck_cluster_count is None:
area = self.width * self.height
self.bottleneck_cluster_count = max(2, int(area / 18))
else:
self.bottleneck_cluster_count = int(bottleneck_cluster_count)
self.bottleneck_edges_per_link = int(bottleneck_edges_per_link)
self.graph = None
self.active_positions = None
# def calculate_defaults(self):
# total_possible = (self.width + 1) * (self.height + 1)
# scale = {"highly_connected": 1.2, "bottlenecks": 0.85, "linear": 0.75}.get(self.topology, 1.0)
# if self.topology == "highly_connected": vf = max(0.0, self.node_drop_fraction * 0.8)
# elif self.topology == "linear": vf = min(0.95, self.node_drop_fraction * 1.2)
# else: vf = self.node_drop_fraction
# est_nodes = int(self.node_factor * scale * total_possible * (1.0 - vf))
# if self.topology == "highly_connected": est_edges = int(3.5 * est_nodes)
# elif self.topology == "bottlenecks": est_edges = int(1.8 * est_nodes)
# else: est_edges = int(1.5 * est_nodes)
# return est_nodes, est_edges
def calculate_defaults(self):
total_possible = self.width * self.height
scale = {"highly_connected": 1.2, "bottlenecks": 0.85, "linear": 0.75}.get(self.topology, 1.0)
# NEW: Use the unified fraction method we just updated above
vf = self._effective_node_drop_fraction()
est_nodes = int(self.node_factor * scale * total_possible * (1.0 - vf))
if self.topology == "highly_connected": est_edges = int(3.5 * est_nodes)
elif self.topology == "bottlenecks": est_edges = int(1.8 * est_nodes)
else: est_edges = int(1.5 * est_nodes)
return est_nodes, est_edges
def calculate_max_capacity(self):
"""Estimates max possible edges for planar-like spatial graph."""
total_possible_nodes = int(self.width * self.height * (1.0 - self.node_drop_fraction))
if self.topology == "highly_connected":
return int(total_possible_nodes * 4.5)
return int(total_possible_nodes * 3.0)
def generate(self):
max_attempts = 15
for attempt in range(max_attempts):
self._build_node_mask()
self._initialize_graph()
self._add_nodes()
nodes = list(self.graph.nodes())
if len(nodes) < 2: continue
if self.topology == "bottlenecks":
self._build_bottleneck_clusters(nodes)
else:
self._connect_all_nodes_by_nearby_growth(nodes)
self._add_edges()
self._remove_intersections()
if self.target_edges > 0:
self._adjust_edges_to_target()
else:
self._enforce_edge_budget()
if not nx.is_connected(self.graph):
self._force_connect_components()
self._remove_intersections()
if nx.is_connected(self.graph):
return self.graph
raise RuntimeError("Failed to generate valid network. Loosen overrides.")
# def _effective_node_drop_fraction(self):
# base = self.node_drop_fraction
# if self.topology == "highly_connected": return max(0.0, base * 0.8)
# if self.topology == "linear": return min(0.95, base * 1.2)
# return base
def _effective_node_drop_fraction(self):
base = self.node_drop_fraction
# Fix: app.py passes "R" when the "Custom" variant is selected
if self.variant == "R":
return base
# Safety net for 'Fixed' ("F") presets
if self.topology == "highly_connected": return max(0.0, base * 0.8)
if self.topology == "linear": return min(0.95, base * 1.2)
return base
def _build_node_mask(self):
all_positions = [(x, y) for x in range(self.width) for y in range(self.height)]
drop_frac = self._effective_node_drop_fraction()
drop = int(drop_frac * len(all_positions))
deactivated = set(random.sample(all_positions, drop)) if drop > 0 else set()
self.active_positions = set(all_positions) - deactivated
def _initialize_graph(self):
self.graph = nx.Graph()
margin_x = max(1, self.width // 4)
margin_y = max(1, self.height // 4)
low_x, high_x = margin_x, self.width - 1 - margin_x
low_y, high_y = margin_y, self.height - 1 - margin_y
if low_x > high_x: low_x, high_x = 0, self.width - 1
if low_y > high_y: low_y, high_y = 0, self.height - 1
middle_active = [p for p in self.active_positions if low_x <= p[0] <= high_x and low_y <= p[1] <= high_y]
if middle_active: seed = random.choice(middle_active)
elif self.active_positions: seed = random.choice(list(self.active_positions))
else: return
self.graph.add_node(tuple(seed))
def _add_nodes(self):
for n in self.active_positions:
if not self.graph.has_node(n):
self.graph.add_node(n)
def _connect_all_nodes_by_nearby_growth(self, nodes):
connected = set()
remaining = set(nodes)
if not remaining: return
current = random.choice(nodes)
connected.add(current)
remaining.remove(current)
while remaining:
candidates = []
for n in remaining:
closest_dist = min([abs(n[0]-c[0]) + abs(n[1]-c[1]) for c in connected])
if closest_dist <= 4:
candidates.append(n)
if not candidates:
best_n = min(remaining, key=lambda r: min(abs(r[0]-c[0]) + abs(r[1]-c[1]) for c in connected))
candidates.append(best_n)
candidate = random.choice(candidates)
neighbors = sorted(list(connected), key=lambda c: abs(c[0]-candidate[0]) + abs(c[1]-candidate[1]))
for n in neighbors[:3]:
if not self._would_create_intersection(n, candidate):
self.graph.add_edge(n, candidate)
break
else:
self.graph.add_edge(neighbors[0], candidate)
connected.add(candidate)
remaining.remove(candidate)
def _compute_edge_count(self):
if self.target_edges > 0: return self.target_edges
n = len(self.graph.nodes())
if self.topology == "highly_connected": return int(3.5 * n)
if self.topology == "bottlenecks": return int(1.8 * n)
return int(random.uniform(1.2, 2.0) * n)
def _add_edges(self):
nodes = list(self.graph.nodes())
if self.topology == "highly_connected": self._add_cluster_dense(nodes, self._compute_edge_count())
elif self.topology == "linear": self._make_linear(nodes)
def _make_linear(self, nodes):
nodes_sorted = sorted(nodes, key=lambda x: (x[0], x[1]))
if not nodes_sorted: return
prev = nodes_sorted[0]
for nxt in nodes_sorted[1:]:
if not self._would_create_intersection(prev, nxt): self.graph.add_edge(prev, nxt)
prev = nxt
def _add_cluster_dense(self, nodes, max_edges):
edges_added = 0
nodes = list(nodes)
random.shuffle(nodes)
dist_limit = 10 if self.target_edges > 0 else 4
for i in range(len(nodes)):
for j in range(i + 1, len(nodes)):
if self.target_edges == 0 and edges_added >= max_edges: return
n1, n2 = nodes[i], nodes[j]
dist = max(abs(n1[0]-n2[0]), abs(n1[1]-n2[1]))
if dist <= dist_limit:
if not self._would_create_intersection(n1, n2):
self.graph.add_edge(n1, n2)
edges_added += 1
def _build_bottleneck_clusters(self, nodes):
self.graph.remove_edges_from(list(self.graph.edges()))
clusters, centers = self._spatial_cluster_nodes(nodes, k=self.bottleneck_cluster_count)
for cluster in clusters:
if len(cluster) < 2: continue
# FIX: Call main connectivity directly
self._connect_all_nodes_by_nearby_growth(cluster)
self._add_cluster_dense(list(cluster), max_edges=max(1, int(3.5 * len(cluster))))
order = sorted(range(len(clusters)), key=lambda i: (centers[i][0], centers[i][1]))
for a_idx, b_idx in zip(order[:-1], order[1:]):
self._add_bottleneck_links(clusters[a_idx], clusters[b_idx], self.bottleneck_edges_per_link)
if not nx.is_connected(self.graph): self._force_connect_components()
def _force_connect_components(self):
components = list(nx.connected_components(self.graph))
while len(components) > 1:
c1, c2 = list(components[0]), list(components[1])
best_pair, min_dist = None, float('inf')
s1 = c1 if len(c1)<30 else random.sample(c1, 30)
s2 = c2 if len(c2)<30 else random.sample(c2, 30)
for u in s1:
for v in s2:
d = (u[0]-v[0])**2 + (u[1]-v[1])**2
if d < min_dist and not self._would_create_intersection(u, v):
min_dist, best_pair = d, (u, v)
if best_pair: self.graph.add_edge(best_pair[0], best_pair[1])
else: break
prev_len = len(components)
components = list(nx.connected_components(self.graph))
if len(components) == prev_len: break
def _spatial_cluster_nodes(self, nodes, k):
nodes = list(nodes)
if k >= len(nodes): return [[n] for n in nodes], nodes[:]
centers = random.sample(nodes, k)
clusters = [[] for _ in range(k)]
for n in nodes:
best_i = min(range(k), key=lambda i: max(abs(n[0]-centers[i][0]), abs(n[1]-centers[i][1])))
clusters[best_i].append(n)
return clusters, centers
def _add_bottleneck_links(self, cluster_a, cluster_b, m):
pairs = []
for u in cluster_a:
for v in cluster_b:
dist = max(abs(u[0]-v[0]), abs(u[1]-v[1]))
pairs.append((dist, u, v))
pairs.sort(key=lambda t: t[0])
added = 0
for _, u, v in pairs:
if added >= m: break
if not self.graph.has_edge(u, v) and not self._would_create_intersection(u, v):
self.graph.add_edge(u, v)
added += 1
def _remove_intersections(self):
pass_no = 0
while pass_no < 5:
pass_no += 1
edges = list(self.graph.edges())
intersections = []
check_edges = random.sample(edges, 400) if len(edges) > 600 else edges
for i in range(len(check_edges)):
for j in range(i+1, len(check_edges)):
e1, e2 = check_edges[i], check_edges[j]
if self._segments_intersect(e1[0], e1[1], e2[0], e2[1]): intersections.append((e1, e2))
if not intersections: break
for e1, e2 in intersections:
if not self.graph.has_edge(*e1) or not self.graph.has_edge(*e2): continue
l1 = (e1[0][0]-e1[1][0])**2 + (e1[0][1]-e1[1][1])**2
l2 = (e2[0][0]-e2[1][0])**2 + (e2[0][1]-e2[1][1])**2
rem = e1 if l1 > l2 else e2
self.graph.remove_edge(*rem)
def _adjust_edges_to_target(self):
current_edges = list(self.graph.edges())
curr_count = len(current_edges)
if curr_count > self.target_edges:
to_remove = curr_count - self.target_edges
sorted_edges = sorted(current_edges, key=lambda e: (e[0][0]-e[1][0])**2 + (e[0][1]-e[1][1])**2, reverse=True)
for e in sorted_edges:
if len(self.graph.edges()) <= self.target_edges: break
self.graph.remove_edge(*e)
if not nx.is_connected(self.graph): self.graph.add_edge(*e)
elif curr_count < self.target_edges:
needed = self.target_edges - curr_count
nodes = list(self.graph.nodes())
attempts = 0
while len(self.graph.edges()) < self.target_edges and attempts < (needed * 30):
attempts += 1
u = random.choice(nodes)
candidates = sorted(nodes, key=lambda n: (n[0]-u[0])**2 + (n[1]-u[1])**2)
if len(candidates) < 2: continue
v = random.choice(candidates[1:min(len(candidates), 10)])
if not self.graph.has_edge(u, v) and not self._would_create_intersection(u, v):
self.graph.add_edge(u, v)
def _enforce_edge_budget(self):
budget = self._compute_edge_count()
while len(self.graph.edges()) > budget:
edges = list(self.graph.edges())
rem = random.choice(edges)
self.graph.remove_edge(*rem)
if not nx.is_connected(self.graph):
self.graph.add_edge(*rem)
break
def _segments_intersect(self, a, b, c, d):
if a == c or a == d or b == c or b == d: return False
def ccw(A,B,C): return (C[1]-A[1]) * (B[0]-A[0]) > (B[1]-A[1]) * (C[0]-A[0])
return ccw(a,c,d) != ccw(b,c,d) and ccw(a,b,c) != ccw(a,b,d)
def _would_create_intersection(self, u, v):
for a, b in self.graph.edges():
if u == a or u == b or v == a or v == b: continue
if self._segments_intersect(u, v, a, b): return True
return False
def _get_intersecting_edge(self, u, v):
for a, b in self.graph.edges():
if u == a or u == b or v == a or v == b: continue
if self._segments_intersect(u, v, a, b): return (a, b)
return None
def get_node_id_str(self, node):
sorted_nodes = get_sorted_nodes(self.graph)
if node in sorted_nodes:
return str(sorted_nodes.index(node) + 1)
return "?"
def manual_add_node(self, x, y):
x, y = int(x), int(y)
# FIX: Bounds check against Width-1
if not (0 <= x < self.width and 0 <= y < self.height): return False, "Out of bounds."
if self.graph.has_node((x, y)): return False, "Already exists."
self.graph.add_node((x, y))
nodes = list(self.graph.nodes())
if len(nodes) > 1:
closest = min([n for n in nodes if n != (x,y)], key=lambda n: (n[0]-x)**2 + (n[1]-y)**2)
if not self._would_create_intersection((x,y), closest): self.graph.add_edge((x,y), closest)
return True, "Node added."
def manual_delete_node(self, x, y):
x, y = int(x), int(y)
if not self.graph.has_node((x, y)): return False, "Node not found."
self.graph.remove_node((x, y))
if len(self.graph.nodes()) > 1 and not nx.is_connected(self.graph):
self._force_connect_components()
return True, "Node removed."
def manual_toggle_edge(self, u, v):
if self.graph.has_edge(u, v):
self.graph.remove_edge(u, v)
if not nx.is_connected(self.graph):
self.graph.add_edge(u, v)
return False, "Cannot remove edge (breaks connectivity)."
return True, "Edge removed."
else:
intersecting_edge = self._get_intersecting_edge(u, v)
if not intersecting_edge:
self.graph.add_edge(u, v)
return True, "Edge added."
else:
a, b = intersecting_edge
id_a = self.get_node_id_str(a)
id_b = self.get_node_id_str(b)
return False, f"Intersect with {id_a}-{id_b}."