Files
didericis ad3f95fa39 Move root experiment scripts into their papers' experiments/ folders
Relocate the standalone Python scripts from the repo root into the
experiments/ folder of the paper each one belongs to:

  plane_depth_sequencing/experiments/
    plane_depth_sequencing.py, draw_quad_sequence.py,
    draw_quad_sequence_diagram.py, extract_sequence.py,
    plane_depth_sequencing_figure.py, quad_sequence_coloring_check.py
  colored_edge_flip_classes/experiments/   colored_edge_flip_class_survey.py
  colored_pentagon_contractions/experiments/ colored_pentagon_contractions.py
  plane_diamond_coloring/experiments/       plane_diamond_coloring.py

Each file that imports lib.* (still in the repo root) or the sibling
plane_depth_sequencing module gets a sys.path shim that prepends the
repo root (computed three levels up) and, where needed, its own dir.
Imports verified to resolve from a neutral working directory.

flip_symmetric_census.py is intentionally left in the root.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-22 10:40:39 -04:00

279 lines
11 KiB
Python

"""Draw a graph with quadrilateral sequence diagram for the plane depth sequencing paper.
Usage:
sage draw_quad_sequence.py --seed 42 --n 7 --output quad_sequence.png
"""
import os, sys
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "..", ".."))) # repo root for `lib`
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__))) # sibling experiment modules
from PIL import Image, ImageDraw
import argparse
from pathlib import Path
from sage.all import graphs, Graph # type: ignore
from sage.misc.randstate import set_random_seed # type: ignore
from plane_depth_sequencing import (
quadrilateral_sequencing,
_quad_vertices,
_level_edge_of_face,
_quad_type,
get_plane_depth_labelling,
)
from lib.tutte_embedding import tutte_embedding
def generate_sequence(seed: int, n: int) -> tuple[list[dict], dict, Graph, list, Graph]:
"""Generate a quadrilateral sequence and return (sequence_data, depth_labelling, original_graph, outer_cycle, deep_embedding_graph)."""
set_random_seed(seed)
g = graphs.RandomTriangulation(n)
g.is_planar(set_embedding=True)
embedding = g.get_embedding()
faces = g.faces(embedding)
outer_cycle = [u for u, _ in faces[0]]
result = quadrilateral_sequencing(g, outer_cycle)
sequence = result['sequence']
move_codes = result['move_codes']
depth_labelling = result['depth_labelling']
g_prime = result['deep_embedding']
move_names = {0: "AD", 1: "LA", 2: "J", 3: "RC"}
quad_type_colors = {
"deep_diamond": (178, 223, 219),
"shallow_diamond": (255, 224, 178),
"s_quad": (248, 187, 208),
}
# Pass 1: collect each quad's level-edge endpoints, apexes, and full vertex set.
raw = []
quads = sequence[:6] # Limit to first 6 for readability
for i, quad in enumerate(quads):
quad_type = _quad_type(quad, depth_labelling)
f1, f2 = list(quad)
level_edge = _level_edge_of_face(f1, depth_labelling)
p, q = list(level_edge)
a = next(v for v in f1 if v not in level_edge)
b = next(v for v in f2 if v not in level_edge)
# Apex with the smaller depth goes on top, larger depth on bottom.
top, bottom = (a, b) if depth_labelling[a] <= depth_labelling[b] else (b, a)
move = move_names[move_codes[i - 1]] if i > 0 else ""
move_label = f"Q_{i+1}" if i == 0 else f"Q_{i+1}^{{{move}}}"
raw.append({
"level": (p, q),
"verts": {p, q, a, b},
"top": top,
"bottom": bottom,
"move": move_label,
"type": quad_type,
"color": quad_type_colors[quad_type],
})
# Pass 2: chain the diamonds. The left/right corners of a diamond are its level
# edge endpoints. A vertex shared with the PREVIOUS quad's level edge was that
# quad's right corner, so it goes on the LEFT here; a vertex shared with the NEXT
# quad's level edge goes on the RIGHT. Apex vertices are centered (top/bottom) and
# impose no left/right constraint, so only level-edge sharing matters.
sequence_data = []
for i, r in enumerate(raw):
p, q = r["level"]
prev_level = set(raw[i - 1]["level"]) if i > 0 else set()
next_level = set(raw[i + 1]["level"]) if i + 1 < len(raw) else set()
p_prev, q_prev = p in prev_level, q in prev_level
p_next, q_next = p in next_level, q in next_level
if p_prev != q_prev: # exactly one shared with prev -> left
left = p if p_prev else q
right = q if p_prev else p
elif p_next != q_next: # else exactly one shared with next -> right
right = p if p_next else q
left = q if p_next else p
else: # no chain constraint: deterministic fallback
right = max(p, q, key=str)
left = q if right == p else p
sequence_data.append({
"left": left,
"right": right,
"top": r["top"],
"bottom": r["bottom"],
"depth_left": depth_labelling[left],
"depth_right": depth_labelling[right],
"depth_top": depth_labelling[r["top"]],
"depth_bottom": depth_labelling[r["bottom"]],
"move": r["move"],
"type": r["type"],
"color": r["color"],
})
return sequence_data, depth_labelling, g, outer_cycle, g_prime
def draw_graph(g_prime: Graph, outer_cycle: list, depth_labelling: dict, width: int, height: int) -> Image.Image:
"""Draw the deep embedding graph with Tutte embedding and depth labels in a square."""
img = Image.new('RGB', (width, height), 'white')
draw = ImageDraw.Draw(img)
# Get Tutte embedding for the deep embedding graph
pos = tutte_embedding(g_prime, outer_cycle)
# Get data bounds
xs = [p[0] for p in pos.values()]
ys = [p[1] for p in pos.values()]
x_min, x_max = min(xs), max(xs)
y_min, y_max = min(ys), max(ys)
x_range = x_max - x_min if x_max > x_min else 1
y_range = y_max - y_min if y_max > y_min else 1
# Create a square region in the center of the image
margin = 30
max_size = min(width, height) - 2 * margin
graph_size = max_size
# Center the square graph horizontally
graph_x_min = (width - graph_size) // 2
graph_x_max = graph_x_min + graph_size
graph_y_min = margin
graph_y_max = margin + graph_size
def data_to_pixel(x: float, y: float) -> tuple[int, int]:
px = graph_x_min + (x - x_min) / x_range * (graph_x_max - graph_x_min)
py = graph_y_min + (y - y_min) / y_range * (graph_y_max - graph_y_min)
return int(px), int(py)
# Draw edges
for u, v in g_prime.edges(labels=False):
px1, py1 = data_to_pixel(pos[u][0], pos[u][1])
px2, py2 = data_to_pixel(pos[v][0], pos[v][1])
# Color level edges differently
if depth_labelling[u] == depth_labelling[v]:
draw.line([(px1, py1), (px2, py2)], fill=(150, 150, 150), width=1)
else:
draw.line([(px1, py1), (px2, py2)], fill=(50, 50, 50), width=1)
# Draw vertices
for v, (x, y) in pos.items():
px, py = data_to_pixel(x, y)
depth = depth_labelling[v]
if v in outer_cycle:
color = (25, 118, 210) # blue
else:
color = (0, 0, 0) # black
draw.ellipse([px-5, py-5, px+5, py+5], fill=color)
# Draw label with vertex ID and depth
label = f"{v}^{depth}"
draw.text((px-12, py-20), label, fill='black')
return img
def draw_diagram(sequence_data: list[dict], depth_labelling: dict, output_path: str):
"""Draw and save the sequence diagram."""
width = 300 + len(sequence_data) * 400
height = 380
img = Image.new('RGB', (width, height), 'white')
draw = ImageDraw.Draw(img)
# Data-to-pixel coordinate mapping
data_x_min = -2.0
data_x_max = 0.5 + len(sequence_data) * 3.5
data_y_min = -1.1
data_y_max = 2.3
pixel_x_min = 80
pixel_x_max = width - 40
pixel_y_min = 40
pixel_y_max = height - 40
def data_to_pixel(x: float, y: float) -> tuple[int, int]:
px = pixel_x_min + (x - data_x_min) / (data_x_max - data_x_min) * (pixel_x_max - pixel_x_min)
py = pixel_y_max - (y - data_y_min) / (data_y_max - data_y_min) * (pixel_y_max - pixel_y_min)
return int(px), int(py)
step_width = 3.5
r = 0.45
# Depth -> data-y: smaller depth higher on screen (larger data-y).
all_depths = [
d for quad in sequence_data
for d in (quad["depth_left"], quad["depth_right"], quad["depth_top"], quad["depth_bottom"])
]
min_d, max_d = min(all_depths), max(all_depths)
y_of = lambda d: 1.0 - (d - min_d) * 0.5
for i, quad_data in enumerate(sequence_data):
x = i * step_width
color = quad_data["color"]
# Place the four corners. The level edge {left,right} is horizontal (both at
# the same depth); the apexes sit above (smaller depth) and below (larger).
p_left = data_to_pixel(x - r, y_of(quad_data["depth_left"]))
p_right = data_to_pixel(x + r, y_of(quad_data["depth_right"]))
p_top = data_to_pixel(x, y_of(quad_data["depth_top"]))
p_bottom = data_to_pixel(x, y_of(quad_data["depth_bottom"]))
# Polygon in cyclic order so the diamond is non-self-intersecting.
corners = [p_left, p_top, p_right, p_bottom]
draw.polygon(corners, fill=color, outline='black', width=2)
for px, py in corners:
draw.ellipse([px-5, py-5, px+5, py+5], fill='black')
# Vertex labels, offset away from the diamond body.
labels = [
(p_left, quad_data["left"], (-18, -6)),
(p_right, quad_data["right"], (10, -6)),
(p_top, quad_data["top"], (-4, -18)),
(p_bottom, quad_data["bottom"], (-4, 8)),
]
for (px, py), vid, (dx, dy) in labels:
draw.text((px + dx, py + dy), str(vid), fill='black')
# Quad move label at the centroid.
cx = sum(p[0] for p in corners) // 4
cy = sum(p[1] for p in corners) // 4
draw.text((cx-15, cy-6), quad_data["move"], fill='black')
# Depth gridline labels on the left of the first quad.
if i == 0:
for d in range(min_d, max_d + 1):
label_px, label_py = data_to_pixel(x - 1.2, y_of(d))
draw.text((label_px-28, label_py-6), f"d={d}", fill=(80, 80, 80))
if output_path:
img.save(output_path)
print(f"Saved diagram to {output_path}")
print(f"Sequence diagram size: {img.size}")
return img
if __name__ == "__main__":
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument("--seed", type=int, default=42, help="Random seed for graph generation")
parser.add_argument("--n", type=int, default=7, help="Number of vertices in the random triangulation")
parser.add_argument("--output", type=str, default="quad_sequence_diagram.png", help="Output file path")
args = parser.parse_args()
print(f"Generating sequence for n={args.n} with seed={args.seed}")
sequence_data, depth_labelling, g, outer_cycle, g_prime = generate_sequence(args.seed, args.n)
print(f"Generated {len(sequence_data)} quadrilaterals")
print(f"Deep embedding has {g_prime.order()} vertices (original had {g.order()})")
# Draw deep embedding graph with depths
graph_width = 300 + len(sequence_data) * 400
graph_height = 500
graph_img = draw_graph(g_prime, outer_cycle, depth_labelling, graph_width, graph_height)
# Draw sequence
seq_width = graph_width
seq_height = 380
seq_img = draw_diagram(sequence_data, depth_labelling, None) # Return image instead of saving
# Combine images vertically
combined_width = graph_width
combined_height = graph_height + seq_height + 20 # 20px gap
combined_img = Image.new('RGB', (combined_width, combined_height), 'white')
combined_img.paste(graph_img, (0, 0))
combined_img.paste(seq_img, (0, graph_height + 20))
combined_img.save(args.output)
print(f"Saved diagram to {args.output}")
print(f"Combined image size: {combined_img.size}")