from typing import Optional
from utils.rng import RNG
def step_room(T: float, heater_on: int, T_out: float, R: float, C: float, P: float,
dt: float, process_sigma: float = 0.0, rng: Optional[RNG] = None) -> float:
''' Simulate one time step of a simple RC room thermal model.
T: Current room temperature (degrees Celsius).
heater_on: Heater state (0=OFF, 1=ON).
T_out: Outside temperature (degrees Celsius).
R: Thermal resistance (degrees Celsius per Watt).
C: Thermal capacitance (Joules per degrees Celsius).
P: Heater power when ON (Watts).
dt: Time step duration (seconds).
process_sigma: Standard deviation of process noise (degrees Celsius).
rng: Optional random number generator for noise.
Returns the updated room temperature after time step dt.
'''
# RC model: dT/dt = (T_out - T)/(R*C) + heater_on * P/C + noise
dT = dt * (((T_out - T) / (R * C)) + (heater_on * (P / C)))
if rng is not None and process_sigma > 0.0:
dT += rng.gauss(0.0, process_sigma)
return T + dT
