Ecological Model Core

Shared scientific primitives for ecological models that use different numerical methods. The crate deliberately contains no simulation engine or Workflow task: GLV and lattice Simulator remain independent runtime-integrated model crates.

The public modules are:

• initial_state: reproducible categorical lattice initial states and verified Workflow artifacts;
• interaction: validated ecological interaction matrices, including the exact antisymmetric Gaussian family used by Dispatcher;
• trajectory: a bounded, allocation-conscious trajectory observer with disabled, terminal-only, and detection modes;
• terminal_state: validated terminal composition and auditable equilibrium, periodic-orbit, and absorbing-state results.

Construction parameters are called recipes, keeping scientific realization instructions distinct from Workflow configuration. Engines submit borrowed abundance slices, so continuous and lattice models retain their native state representations and only copy the bounded samples the selected observer mode needs.

The crate never reads or resolves Workflow task configuration. Callers provide ordinary resolved values (Vec, slices, PathBuf, recipes, and descriptors); an orchestrator or example owns configuration decoding and path-key resolution.

use ecological_model_core::trajectory::{
    TerminalPolicy, TrajectoryObservationPolicy, TrajectoryObserver,
};

let observer = TrajectoryObserver::from_policy(
    TrajectoryObservationPolicy::TerminalOnly(TerminalPolicy {
        sample_interval_iterations: 100,
        trailing_window_samples: 20,
    }),
)?;
assert!(observer.is_some());
# Ok::<(), Box<dyn std::error::Error>>(())

The crate is a clean-start API. It does not read artifacts produced by the former ecological-initial-state crate.