Source code for mercurial.impressions.persistence

"""Impression formation and entropy‑governed persistence."""

from typing import Callable

import numpy as np
from scipy.integrate import odeint




class ImpressionDynamics:
    """Implements MERCURIAL A.18 impression dynamics."""

    def __init__(
        self,
        alpha_form: float = 0.1,
        gamma_form: float = 0.01,
        gamma0: float = 0.001,
        S_crit: float = 10.0,
        k_eff: float = 1.0,
    ):
        self.alpha = alpha_form
        self.gamma_form = gamma_form
        self.gamma0 = gamma0
        self.S_crit = S_crit
        self.k_eff = k_eff



    def formation_rate(
        self,
        emotional_salience: float,
        repetition: float,
        attention: float,
        current_intensity: float,
    ) -> float:
        return (
            self.alpha * emotional_salience * repetition * attention
            - self.gamma_form * current_intensity
        )




    def decay_rate(self, entropy: float) -> float:
        return self.gamma0 * (entropy / self.S_crit)




    def persistence_time(self, entropy: float) -> float:
        tau0 = 86400.0  # 1 day in seconds
        return tau0 * np.exp((self.S_crit - entropy) / self.k_eff)




    def evolve_impression(
        self, I0: float, t_span: np.ndarray, entropy_function: Callable[[float], float]
    ) -> np.ndarray:
        def dI_dt(I, t):
            S_t = entropy_function(t)
            gamma = self.decay_rate(S_t)
            return -gamma * I

        return odeint(dI_dt, I0, t_span).flatten()