Optimization for layered graph layouts¶

import networkx as nx
from IPython.display import SVG
from matplotlib import pyplot as plt

from vizopt.animation import SnapshotCallback
from vizopt.base import OptimConfig
from vizopt.templates.layered_graph import LayeredGraphOptimizer

# Build a simple DAG
dag = nx.DiGraph()
dag.add_edges_from(
    [
        ("A", "B"),
        ("A", "C"),
        ("B", "D"),
        ("B", "E"),
        ("C", "E"),
        ("C", "F"),
        ("D", "G"),
        ("E", "G"),
        ("F", "G"),
    ]
)

optimizer = LayeredGraphOptimizer(
    dag, min_distance=1.5, preferred_edge_vector=(1.0, 0.0), weight_edge_direction=0.0
)
optimizer.optimize(OptimConfig(n_iters=5000, learning_rate=1e-2))

optimizer.plot()
plt.title("Layered graph layout (standard direction → (1, 0))")
plt.show()

snapshot_cb = SnapshotCallback(every=50)
optimizer = LayeredGraphOptimizer(
    dag, min_distance=1.5, preferred_edge_vector=(1.0, 0.0), weight_edge_direction=0.0
)
optimizer.optimize(OptimConfig(n_iters=5000, learning_rate=3e-3), callback=snapshot_cb)

svg = optimizer.animate_svg(snapshot_cb, fps=12, size=500)
SVG(data=svg)