embrs.fire_simulator.wind#

Wind representation that defines the wind conditions for a simulation and calculates the effect on fire propagation

class embrs.fire_simulator.wind.Wind(forecast: list, time_step: float)#

Wind class that specifies the wind conditions for a given simulation.

Parameters:

  • forecast (list) – list of tuples representing the wind vector at equally spaced instants in time. Each element represents (speed (m/s), direction (deg)) at an instant.

  • time_step (float) – time step between each point in ‘forecast’ (in minutes)

property curr_index: int#

Current index the wind is on within its forecast.

property forecast: list#

List of tuples representing the wind vector at equally spaced instants in time.

Each element represents (speed (m/s), direction (deg)) at an instant.

interpolate_parameters(wind_speed: float) → Tuple[float, float, float]#

Calculates the parametes for the Lorentzian function based on the input wind speed. Interpolates a series of Lorentzian fits to determine the parameters.

Parameters:

wind_speed (float) – wind speed in km/h to find parameters for

Returns:

Peak amplitude (A), Full width at half maximum (gamma), and constant offset (C) of the Lorentzian

Return type:

Tuple[float, float, float]

interpolate_wind_adjustment(wind_speed_kmh: float, direction: float) → float#

Calculates the alpha_w parameter which models the probability adjustment due to the wind. Interpolates a series of lorentzian functions that define the adjustment factor.

Parameters:

  • wind_speed_kmh (float) – wind speed in km/h

  • direction (float) – direction of wind in degrees relative to the propagation direction being considered

Returns:

wind adjustment factor, alpha_w

Return type:

float

lorentzian(x: float, A: float, gamma: float, C: float) → float#

Calculate the output of a Lorentzian function with the given input parameters.

Parameters:

  • x (float) – Point to calculate the output of the Lorentzian for, representing the relative angle in degrees.

  • A (float) – Peak amplitude of the Lorentzian peak.

  • gamma (float) – Scale parameter related to the full width at half maximum (FWHM) of the peak.

  • C (float) – Constant baseline offset of the Lorentzian peak.

Returns:

The value of the Lorentzian function at point x.

Return type:

float

property time_step: float#

Time step between each point in the wind’s ‘forecast’ (in minutes).

property vec: list#

Current wind conditions as a 2D vector [x velocity (m/s), y velocity (m/s)].

property wind_dir_deg: float#

Current direction of the wind (deg).

property wind_speed: float#

Current speed of the wind (m/s).

Classes

Wind(forecast, time_step)

Wind class that specifies the wind conditions for a given simulation.