earths 0.0.1

High-fidelity Earth simulation engine — orbit, atmosphere, geology, hydrology, biosphere, terrain, lighting, rendering, satellites, and temporal systems with full scientific coupling
Documentation 
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pub struct HeatWave {
    pub max_temperature_c: f64,
    pub duration_days: u32,
    pub relative_humidity_percent: f64,
}
impl HeatWave {
    pub fn heat_index_c(&self) -> f64 {
        let t = self.max_temperature_c;
        let rh = self.relative_humidity_percent;
        let t_f = t * 9.0 / 5.0 + 32.0;
        let hi_f = -42.379 + 2.04901523 * t_f + 10.14333127 * rh
            - 0.22475541 * t_f * rh
            - 6.83783e-3 * t_f * t_f
            - 5.481717e-2 * rh * rh
            + 1.22874e-3 * t_f * t_f * rh
            + 8.5282e-4 * t_f * rh * rh
            - 1.99e-6 * t_f * t_f * rh * rh;
        (hi_f - 32.0) * 5.0 / 9.0
    }
    pub fn wet_bulb_temperature_c(&self) -> f64 {
        let t = self.max_temperature_c;
        let rh = self.relative_humidity_percent;
        t * (0.151977 * (rh + 8.313659_f64).sqrt()).atan() + (t + rh).atan()
            - (rh - 1.676331).atan()
            + 0.00391838 * rh.powf(1.5) * (0.023101 * rh).atan()
            - 4.686035
    }
    pub fn danger_level(&self) -> &'static str {
        let hi = self.heat_index_c();
        if hi >= 54.0 {
            "Extreme danger"
        } else if hi >= 41.0 {
            "Danger"
        } else if hi >= 32.0 {
            "Extreme caution"
        } else if hi >= 27.0 {
            "Caution"
        } else {
            "Normal"
        }
    }
    pub fn excess_mortality_factor(&self) -> f64 {
        let threshold = 30.0;
        if self.max_temperature_c <= threshold {
            1.0
        } else {
            1.0 + 0.03 * (self.max_temperature_c - threshold) * self.duration_days as f64
        }
    }
}
pub fn saturation_vapor_pressure_pa(temp_c: f64) -> f64 {
    610.78 * (17.27 * temp_c / (temp_c + 237.3)).exp()
}
pub fn dew_point_c(temp_c: f64, relative_humidity: f64) -> f64 {
    let a = 17.27;
    let b = 237.3;
    let alpha = a * temp_c / (b + temp_c) + (relative_humidity / 100.0).ln();
    b * alpha / (a - alpha)
}