Force physics

Force view combines four effects. The controls are intentionally broad enough to produce visibly different behavior.

Setting	Effect	Typical direction
center_force	Pulls every free node toward the canvas origin	Higher makes a tighter cluster
repel_force	Pushes every pair of nodes apart	Higher spreads dense graphs
link_force	Multiplies the spring force of every link	Higher makes links react faster
link_distance	Scales every link's preferred length	Higher creates more space
damping	Retains velocity between frames	Lower settles sooner; higher feels lively

Configure these values when creating the canvas:

canvas = Canvas(
    center_force=0.08,
    repel_force=7,
    link_force=0.55,
    link_distance=190,
    damping=0.92,
)

Or update a running simulation:

canvas.configure_physics(
    center_force=0.2,
    repel_force=12,
    link_force=1.2,
    link_distance=240,
    damping=0.86,
)

The movable Controls panel changes the first four values directly. Its sliders range from nearly disabled to deliberately strong.

Per-link behavior

Canvas.link() also accepts length and elasticity. Global link distance scales each link's individual length, and global link force multiplies each link's elasticity.

soft = canvas.link(a, b, length=100, elasticity=0.015)
firm = canvas.link(b, c, length=200, elasticity=0.08)

Fixed nodes

A fixed node does not receive gravity, repulsion, or spring motion:

anchor = canvas.add_node("Anchor", fixed=True)
canvas.update_node(anchor, fixed=False)  # Release it later.

If a node seems not to obey the controls, check its fixed property first.