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基础弧线图（单向流向）
基础弧线图（单向流向）
Python65 行
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.patches import FancyArrowPatch
COLORS = ["#A8552E", "#35666E", "#D0A64F", "#3F2E18", "#7E8F52"]
BG = "#F7F3EC"
# 起点 → 终点（用索引表示）
nodes = ["A", "B", "C", "D", "E"]
edges = [
(0, 1, 20),
(0, 2, 15),
(1, 3, 25),
(2, 3, 18),
(1, 4, 12),
(3, 4, 22),
(2, 4, 10),
]
n = len(nodes)
# 节点放在上半圆的弧上
angles = np.linspace(np.pi, 0, n)
xs = np.cos(angles)
ys = np.sin(angles)
fig, ax = plt.subplots(figsize=(10, 6))
# 画节点
for i, (x, y, name) in enumerate(zip(xs, ys, nodes)):
ax.scatter(x, y, s=600, color=COLORS[i],
edgecolor="white", linewidth=2.0, zorder=5)
ax.text(x, y - 0.18, name, ha="center", va="top",
fontsize=13, color=COLORS[3], fontweight="bold")
# 画弧线
for src, tgt, weight in edges:
x1, y1 = xs[src], ys[src]
x2, y2 = xs[tgt], ys[tgt]
# 用 FancyArrowPatch 的 arc3 画弧
# rad 控制弧的弯曲方向：正值向上，负值向下
rad = 0.2 if src < tgt else -0.2
arrow = FancyArrowPatch(
(x1, y1), (x2, y2),
connectionstyle=f"arc3,rad={rad}",
arrowstyle="-|>",
mutation_scale=15,
color=COLORS[src],
linewidth=1.5 + weight * 0.05,
alpha=0.55,
zorder=3,
)
ax.add_patch(arrow)
ax.set_xlim(-1.4, 1.4)
ax.set_ylim(-0.4, 1.4)
ax.set_aspect("equal")
ax.axis("off")
ax.set_title("Arc Diagram — Basic",
fontsize=15, color=COLORS[3], pad=12)
plt.tight_layout()
plt.show()线性弧线图（节点在一条线上）
线性弧线图（节点在一条线上）
Python72 行
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.patches import FancyArrowPatch
COLORS = ["#A8552E", "#35666E", "#D0A64F", "#3F2E18", "#7E8F52"]
BG = "#F7F3EC"
nodes = ["A", "B", "C", "D", "E", "F", "G"]
edges = [
(0, 2, 15), (0, 4, 10), (1, 3, 20), (1, 5, 12),
(2, 4, 18), (2, 6, 8), (3, 5, 25), (4, 6, 14),
(0, 6, 5), (1, 6, 7),
]
n = len(nodes)
xs = np.arange(n)
fig, ax = plt.subplots(figsize=(12, 8))
# ============ 关键：弧高随跨度增长 + 同侧分层错开 ============
BASE_H = 0.22 # 基础弧高
SCALE = 0.14 # 跨度带来的额外弧高
max_span = max(abs(t - s) for s, t, _ in edges)
# 先按跨度排序，再奇偶交替分配到上下两侧，避免一侧过挤
edges_sorted = sorted(edges, key=lambda e: abs(e[1] - e[0]))
up_edges, down_edges = [], []
for i, e in enumerate(edges_sorted):
(up_edges if i % 2 == 0 else down_edges).append(e)
def draw_group(group, sign):
"""sign=+1 向上，-1 向下；同侧按跨度排序，依次加大弧高避免重叠"""
group_sorted = sorted(group, key=lambda e: abs(e[1] - e[0]))
for level, (src, tgt, weight) in enumerate(group_sorted):
x1, x2 = xs[src], xs[tgt]
span = abs(x2 - x1)
h = BASE_H + SCALE * span + level * 0.10
rad = sign * (2 * h / span)
arrow = FancyArrowPatch(
(x1, 0), (x2, 0),
connectionstyle=f"arc3,rad={rad}",
arrowstyle="-|>",
mutation_scale=14,
color=COLORS[src % len(COLORS)],
linewidth=1.5 + weight * 0.04,
alpha=0.6,
zorder=3,
)
ax.add_patch(arrow)
draw_group(up_edges, +1)
draw_group(down_edges, -1)
# 画节点
for i, (x, name) in enumerate(zip(xs, nodes)):
ax.scatter(x, 0, s=500, color=COLORS[i % len(COLORS)],
edgecolor="white", linewidth=2.0, zorder=5)
ax.text(x, -0.08, name, ha="center", va="top",
fontsize=12, color=COLORS[3], fontweight="bold")
# ============ 动态 ylim：按实际最大弧高留白 ============
max_h = BASE_H + SCALE * max_span + max(len(up_edges), len(down_edges)) * 0.10
ax.set_xlim(-0.5, n - 0.5)
ax.set_ylim(-max_h - 0.35, max_h + 0.25)
ax.axis("off") # 去掉 set_aspect("equal")，避免 y 轴被压扁
ax.set_title("Arc Diagram — Linear Layout",
fontsize=15, color=COLORS[3], pad=12)
plt.tight_layout()
plt.show()按流量着色 + 箭头方向
按流量着色 + 箭头方向
Python80 行
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.patches import FancyArrowPatch
from matplotlib.lines import Line2D
COLORS = ["#A8552E", "#35666E", "#D0A64F", "#3F2E18", "#7E8F52"]
BG = "#F7F3EC"
nodes = ["USA", "China", "Germany", "Japan", "Brazil", "India", "UK"]
edges = [
(0, 1, 50), (0, 2, 30), (0, 3, 25),
(1, 4, 20), (1, 5, 35), (1, 6, 15),
(2, 5, 18), (3, 5, 12), (4, 6, 10),
(5, 6, 8), (0, 5, 22), (2, 4, 14),
]
n = len(nodes)
xs = np.arange(n)
fig, ax = plt.subplots(figsize=(13, 7))
# ============ 关键：弧高随跨度增长（不是固定 rad，也不是固定弧高） ============
BASE_H = 0.22 # 短边的基础弧高
SCALE = 0.13 # 跨度带来的额外弧高系数
max_span = max(abs(t - s) for s, t, _ in edges)
# 先按"方向"分组，上下交替时同侧多条边再错开
up_edges, down_edges = [], []
for k, (src, tgt, w) in enumerate(edges):
(up_edges if k % 2 == 0 else down_edges).append((src, tgt, w))
def draw_group(group, sign):
"""sign=+1 向上，-1 向下；同侧按跨度排序，依次加大弧高避免重叠"""
group_sorted = sorted(group, key=lambda e: abs(e[1] - e[0]))
for level, (src, tgt, weight) in enumerate(group_sorted):
x1, x2 = xs[src], xs[tgt]
span = abs(x2 - x1)
# 弧高 = 基础 + 跨度贡献 + 同侧层叠偏移
h = BASE_H + SCALE * span + level * 0.10
rad = sign * (2 * h / span)
arrow = FancyArrowPatch(
(x1, 0), (x2, 0),
connectionstyle=f"arc3,rad={rad}",
arrowstyle="-|>",
mutation_scale=13,
color=COLORS[src % len(COLORS)],
linewidth=1.2 + weight * 0.06,
alpha=0.55,
zorder=3,
)
ax.add_patch(arrow)
draw_group(up_edges, +1)
draw_group(down_edges, -1)
# 节点
for i, (x, name) in enumerate(zip(xs, nodes)):
ax.scatter(x, 0, s=700, color=COLORS[i % len(COLORS)],
edgecolor="white", linewidth=2.5, zorder=5)
ax.text(x, -0.08, name, ha="center", va="top",
fontsize=11, color=COLORS[3], fontweight="bold")
# ============ 动态计算 ylim：按实际最大弧高留白 ============
max_h = BASE_H + SCALE * max_span + max(len(up_edges), len(down_edges)) * 0.10
ax.set_xlim(-0.6, n - 0.4)
ax.set_ylim(-max_h - 0.45, max_h + 0.25)
ax.axis("off")
ax.set_title("Arc Diagram — Flow by Source",
fontsize=15, color=COLORS[3], pad=12)
handles = [Line2D([0], [0], color=COLORS[i % len(COLORS)],
linewidth=2.5, label=nodes[i])
for i in range(len(nodes))]
ax.legend(handles=handles, frameon=False, fontsize=10,
labelcolor=COLORS[3], loc="upper right", ncol=2)
plt.tight_layout()
plt.show()圆弧布局
圆弧布局
Python61 行
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.patches import FancyArrowPatch
COLORS = ["#A8552E", "#35666E", "#D0A64F", "#3F2E18", "#7E8F52"]
BG = "#F7F3EC"
nodes = ["A", "B", "C", "D", "E", "F", "G", "H"]
edges = [
(0, 2), (0, 5), (1, 4), (1, 6), (2, 5),
(3, 7), (4, 7), (2, 6), (0, 7), (3, 5),
]
n = len(nodes)
angles = np.linspace(0, 2 * np.pi, n, endpoint=False)
xs = np.cos(angles)
ys = np.sin(angles)
fig, ax = plt.subplots(figsize=(9.5, 9.5))
# 画弧
for src, tgt in edges:
x1, y1 = xs[src], ys[src]
x2, y2 = xs[tgt], ys[tgt]
# 计算弧度方向：让弧向圆心弯
mid_angle = (angles[src] + angles[tgt]) / 2
rad = 0.3 if np.cos(mid_angle) > 0 else -0.3
arrow = FancyArrowPatch(
(x1, y1), (x2, y2),
connectionstyle=f"arc3,rad={rad}",
arrowstyle="-|>",
mutation_scale=12,
color=COLORS[src % len(COLORS)],
linewidth=1.5,
alpha=0.5,
zorder=3,
)
ax.add_patch(arrow)
# 画节点
for i, (x, y, name) in enumerate(zip(xs, ys, nodes)):
ax.scatter(x, y, s=600, color=COLORS[i % len(COLORS)],
edgecolor="white", linewidth=2.5, zorder=5)
# 标签在圆外
offset = 0.15
ax.text(x * (1 + offset), y * (1 + offset), name,
ha="center", va="center",
fontsize=13, color=COLORS[3], fontweight="bold")
ax.set_xlim(-1.5, 1.5)
ax.set_ylim(-1.5, 1.5)
ax.set_aspect("equal")
ax.axis("off")
ax.set_title("Arc Diagram — Circular Layout",
fontsize=15, color=COLORS[3], pad=12)
plt.tight_layout()
plt.show()带权重的弧线图
带权重的弧线图
Python79 行
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.patches import FancyArrowPatch, PathPatch
from matplotlib.path import Path
COLORS = ["#A8552E", "#35666E", "#D0A64F", "#3F2E18", "#7E8F52", "#8A6D3B"]
BG = "#F7F3EC"
nodes = ["Source 1", "Source 2", "Source 3",
"Sink 1", "Sink 2", "Sink 3"]
edges = [
(0, 3, 40), (0, 4, 25), (0, 5, 15),
(1, 3, 30), (1, 4, 35), (1, 5, 20),
(2, 3, 20), (2, 4, 15), (2, 5, 45),
]
n = len(nodes)
xs = np.arange(n)
fig, ax = plt.subplots(figsize=(12, 7.5))
# ============ 关键：手动构造二次贝塞尔，顶点高度可控 ============
BASE_H = 0.35 # 基础弧高
SCALE = 0.15 # 跨度带来的额外弧高
LAYER = 0.18 # 同侧相邻层的间隔
max_span = max(abs(t - s) for s, t, _ in edges)
edges_sorted = sorted(edges, key=lambda e: abs(e[1] - e[0]))
for level, (src, tgt, weight) in enumerate(edges_sorted):
x1, x2 = xs[src], xs[tgt]
span = abs(x2 - x1)
# 弧顶高度 = 基础 + 跨度贡献 + 层叠偏移
h = BASE_H + SCALE * span + level * LAYER
# 二次贝塞尔：起点、控制点、终点
# 控制点放在中点上方 h*2 处（二次贝塞尔顶点 = 控制点高度的一半）
xm = (x1 + x2) / 2
ctrl = (xm, 2 * h) # 控制点
verts = [(x1, 0.05), ctrl, (x2, 0.05)]
codes = [Path.MOVETO, Path.CURVE3, Path.CURVE3]
path = Path(verts, codes)
# 箭头用 FancyArrowPatch 沿路径绘制
arrow = FancyArrowPatch(
path=path,
arrowstyle="-|>",
mutation_scale=14,
color=COLORS[src],
linewidth=weight * 0.15,
alpha=0.55,
zorder=3,
)
ax.add_patch(arrow)
# 节点
for i in range(3):
ax.scatter(xs[i], 0, s=800, color=COLORS[i],
edgecolor="white", linewidth=2.5, zorder=5)
ax.text(xs[i], -0.12, nodes[i], ha="center", va="top",
fontsize=11, color=COLORS[3], fontweight="bold")
for i in range(3, 6):
ax.scatter(xs[i], 0, s=800, color=COLORS[i],
edgecolor="white", linewidth=2.5, zorder=5)
ax.text(xs[i], -0.12, nodes[i], ha="center", va="top",
fontsize=11, color=COLORS[3], fontweight="bold")
# ============ 动态 ylim ============
max_h = BASE_H + SCALE * max_span + (len(edges_sorted) - 1) * LAYER
ax.set_xlim(-0.6, n - 0.4)
ax.set_ylim(-0.6, max_h + 0.4)
ax.axis("off")
ax.set_title("Arc Diagram — Weighted Flows",
fontsize=15, color=COLORS[3], pad=12)
plt.tight_layout()
plt.show()