Field constants

Prefilled StateFieldSpec handles for the fields a step reads or writes. Use them directly when declaring a step's state_reads/state_writes, or call one to override an attribute inline (for example POSITION(heritable=False)). The right column gives the underlying state field name.

State fields

Importable from jax_morph. Present on every generated state.

Constant	Field	Notes
POSITION	position	Cell-centre coordinates, shape (n_space_dim,); filled by the constructor.
RADIUS	radius	Per-cell radius.
CELLTYPE	celltype	One-hot cell type, shape (n_types,); filled by the constructor.
ALIVE	alive	Boolean liveness mask; dtype=bool, defaults to False.
TIME	t	Simulation time; global scope, defaults to 0.0.

Physics fields

Importable from jax_morph.physics. Added to the state by the physics steps that consume them; all are per-cell and heritable.

Constant	Field	Notes
GROWTH_RATE	growth_rate	Per-cell radial growth rate, read by SaturatingCellGrowth.
DIVISION_RATE	division_rate	Per-cell division propensity, read by Division.
DEATH_RATE	death_rate	Per-cell death propensity, read by Death.
ACTIVE_SPEED	active_speed	Per-cell self-propulsion speed, read by ActiveBrownianDynamics2D.
ACTIVE_HEADING	active_heading	Per-cell heading angle, read by ActiveBrownianDynamics2D.