lib.py

from os import listdir
from os.path import isfile, join
from time import sleep
from math import sqrt
#from stringdist.pystringdist.levenshtein import levenshtein as ed
from nltk.tokenize import sent_tokenize, word_tokenize
from nltk.corpus import stopwords
import math
import requests
from sklearn.metrics import mean_squared_error, r2_score, median_absolute_error, mean_squared_log_error, mean_absolute_error, classification_report
from datetime import datetime
import pytz
import geocoder
import numpy as np


class Lib:
    
    # Stephan Boltzmann constant (W m-2 K-4)
    SB = 5.670373e-8
    # heat capacity of dry air at constant pressure (J kg-1 K-1)
    C_PD = 1003.5
    # heat capacity of water vapour at constant pressure (J kg-1 K-1)
    C_PV = 1865
    # gas constant for dry air (rd), J/(kg*degK)
    GAS_CONSTANT_FOR_DRY_AIR = 287.04
    # acceleration of gravity (m s-2)
    G = 9.8
    # the density of water kg m-3
    DENSITY_OF_WATER = 1000 
    SOLAR_CONSTANT_MJ_MIN = 0.08202 # Solar constant (G_sc) in MJ/m²/min 
    SOLAR_CONSTANT_MJ_HOUR = 4.9212 # Solar constant (G_sc) in MJ/m²/h 
    SOLAR_CONSTANT_W_PER_M2 = 1367 # Solar constant (G_sc) in W/m² 
    ALBEDO = 0.23  # Albedo coefficient for grass reference surface
    CP = 1.013e-3  # Specific heat of air at constant pressure (MJ/kg°C)
    EPSILON = 0.622  # Ratio molecular weight of water vapor/dry air
    PI = math.pi
    LATENT_HEAT_OF_VAPORIZATION = 2.45  # Latent heat of vaporization for water (MJ/kg)
    SIGMA = 0.000000004903  # Stefan-Boltzmann constant in MJ/K4/m2/day
    
    
    def __init__(self, *args, **kwargs):
        pass
    
    @staticmethod
    def et0_penman_monteith_daily_v3(row):
        # input variables
        # T = 25.0  # air temperature in degrees Celsius
        # RH = 60.0  # relative humidity in percent
        # u2 = 2.0  # wind speed at 2 m height in m/s
        # Rs = 15.0  # incoming solar radiation in MJ/m2/day
        # lat = 35.0  # latitude in degrees
        
        ta_mean_c, rh_mean, u2_mean, rs_daily, lat, elevation, doy =  row['ta_mean'],  row['rh_mean'], row['ws_mean'], row['rs_daily'], row['lat'], row['elevation'], row['doy']
        
        # constants
        ALBEDO = 0.23  # Albedo coefficient for grass reference surface
        SIGMA = 0.000000004903  # Stefan-Boltzmann constant in MJ/K4/m2/day
        G = 0  # Soil heat flux density (MJ/m2/day)

        ta_mean_k = ta_mean_c + 273.16  # air temperature in Kelvin
        
        # saturation vapor pressure in kPa
        es = 0.6108 * math.exp((17.27 * ta_mean_c) / (ta_mean_c + 237.3))

        # actual vapor pressure in kPa
        ea = es * (rh_mean / 100)
        
        # in the absence of rh_max and rh_min
        #ea = (rh_mean / 100) * es
        
        # when using equipement where errors in estimation rh min can be large or when rh data integrity are in doubt use only rh_max term
        #ea = ea_min_term  
        
        delta = Lib.slope_saturation_vapor_pressure_curve(ta_mean_c) # slope of the vapor pressure curve in kPa/K
        
        # psychrometric constant in kPa/K
        gamma = Lib.psychrometric_constant(elevation, ta_mean_c)
        
        # Calculate u2
        u2 = u2_mean
        
        # Calculate extraterrestrial radiation
        ra = Lib.extraterrestrial_radiation(lat, doy)
        
        # Calculate clear sky solar radiation
        rso = (0.75 + (2e-5 * elevation)) * ra
        
        # Calculate net solar shortwave radiation 
        rns = (1 - ALBEDO) * rs_daily
        
        # Calculate net longwave radiation
        
        rnl = SIGMA * (math.pow(ta_mean_k, 4) * (0.34 - (0.14 * math.sqrt(ea))) * ((1.35 * (rs_daily / rso)) - 0.35))
        
        # Calculate net radiation
        rn = rns - rnl
        
        
        # decompose et0 to two terms to facilitate the calculation
        """rng = 0.408 * rn
        radiation_term = ((delta) / (delta + (gamma * (1 + 0.34 * u2)))) * rng
        pt = (gamma) / (delta + gamma * (1 + (0.34 * u2)))
        tt = ((900) / (ta_mean + 273) ) * u2
        wind_term = pt * tt * (es - ea)
        et0 = radiation_term + wind_term """
        
        #et0 = ((0.408 * delta * (rn - G)) + gamma * (((900 * u2 * (es - ea)) / (ta_mean_c + 273)))) / (delta + (gamma * (1 + (0.34 * u2))))


        gamma1 = gamma * (1 + 0.34 * u2)

        den = delta + gamma1
        num1 = (0.408 * delta * rn) / den
        num2 = (gamma * (es - ea) * 900 * u2 / (ta_mean_c + 273)) / den
        pet = num1 + num2
        et0 = pet
        # output result
        return et0
    
    @staticmethod
    def et0_penman_monteith_daily(row):
        # input variables
        # T = 25.0  # air temperature in degrees Celsius
        # RH = 60.0  # relative humidity in percent
        # u2 = 2.0  # wind speed at 2 m height in m/s
        # Rs = 15.0  # incoming solar radiation in MJ/m2/day
        # lat = 35.0  # latitude in degrees
        
        G = 0  # Soil heat flux density (MJ/m2/day)
        
        ta_max, ta_min, rh_max, rh_min, u2_mean, rs_mean, lat, elevation, doy =  row['ta_max'], row['ta_min'], row['rh_max'], row['rh_min'], row['ws_mean'], row['rs_mean'], row['lat'], row['elevation'], row['doy']
        
        rs_mean *= 0.0864  # convert watts per square meter to megajoules per square meter 0.0288 = 60x60x8hours or 0.0864 for 24 hours

        ta_mean = (ta_max + ta_min) / 2
        ta_max_kelvin = ta_max + 273.16  # air temperature in Kelvin
        ta_min_kelvin = ta_min + 273.16  # air temperature in Kelvin
        
        # saturation vapor pressure in kPa
        es_max = 0.6108 * math.exp((17.27 * ta_max) / (ta_max + 237.3))
        es_min = 0.6108 * math.exp((17.27 * ta_min) / (ta_min + 237.3))
        es = (es_max + es_min) / 2
        
        # actual vapor pressure in kPa
        ea_max_term = es_max * (rh_min / 100)
        ea_min_term = es_min * (rh_max / 100)
        ea = (ea_max_term + ea_min_term) / 2
        
        # in the absence of rh_max and rh_min
        #ea = (rh_mean / 100) * es
        
        # when using equipement where errors in estimation rh min can be large or when rh data integrity are in doubt use only rh_max term
        #ea = ea_min_term  
        
        delta = Lib.slope_saturation_vapor_pressure_curve(ta_mean) # slope of the vapor pressure curve in kPa/K
        
        # psychrometric constant in kPa/K
        gamma = Lib.psychrometric_constant(elevation, ta_mean)
        
        # Calculate u2
        u2 = u2_mean
        
        # Calculate extraterrestrial radiation
        ra = Lib.extraterrestrial_radiation_daily(lat, doy)
        
        # Calculate clear sky solar radiation
        rso = (0.75 + (2e-5 * elevation)) * ra
        
        # Calculate net solar shortwave radiation 
        rns = (1 - Lib.ALBEDO) * rs_mean
        
        # Calculate net longwave radiation
        
        rnl = Lib.SIGMA * (((math.pow(ta_max_kelvin, 4) + math.pow(ta_min_kelvin, 4)) / 2) * (0.34 - (0.14 * math.sqrt(ea))) * ((1.35 * (rs_mean / rso)) - 0.35))
        
        # Calculate net radiation
        rn = rns - rnl
        
        
        # decompose et0 to two terms to facilitate the calculation
        """rng = 0.408 * rn
        radiation_term = ((delta) / (delta + (gamma * (1 + 0.34 * u2)))) * rng
        pt = (gamma) / (delta + gamma * (1 + (0.34 * u2)))
        tt = ((900) / (ta_mean + 273) ) * u2
        wind_term = pt * tt * (es - ea)
        et0 = radiation_term + wind_term """
        
        CD = 0.34
        CN = 900
        
        et0 = ((0.408 * delta * (rn - G)) + gamma * (((CN * u2 * (es - ea)) / (ta_mean + 273)))) / (delta + (gamma * (1 + (CD * u2))))

        # output result
        return et0
    
    @staticmethod
    def et0_penman_monteith_hourly(
        row,
        ta_column_name,
        rs_column_name,
        rh_column_name,
        ws_column_name,
        tz_offset,
        reference_crop,
        ):
        # input variables
        # T = 25.0  # air temperature in degrees Celsius
        # RH = 60.0  # relative humidity in percent
        # u2 = 2.0  # wind speed at 2 m height in m/s
        # Rs = 15.0  # incoming solar radiation in MJ/m2/day
        # lat = 35.0  # latitude in degrees
        
        ta_c, rs, rh, u2, lat, elevation, doy, lon, hod =  row[ta_column_name], row[rs_column_name], row[rh_column_name], row[ws_column_name], row['lat'], row['elevation'], row['doy'], row['lon'], row['hod']
        
        # convert units
        rs *= 3.6e-3  # convert watts per square meter to megajoules per square meter 0.0288 = 60x60x8hours or 0.0864 for 24 hours
        ta_k = ta_c + 273.16  # air temperature in Kelvin
        
        lambda_heat = Lib.latent_heat_of_vaporization(ta_c)
        
        # saturation vapor pressure in kPa
        es = Lib.saturation_vapor_pressure(ta_c)
        
        ea = Lib.actual_vapor_pressure(ta_c, rh)
        
        epsilon_net = Lib.net_emissivity_of_surface(ta_c, rh)
        
        # slope of the vapor pressure curve in kPa/K
        delta = Lib.slope_saturation_vapor_pressure_curve(ta_c)
        
        # psychrometric constant in kPa/K
        gamma = Lib.psychrometric_constant(elevation, ta_c)
        
        # Calculate extraterrestrial radiation
        ra = Lib.extraterrestrial_radiation_hourly_v3(doy, lat, lon, hod, tz_offset)
        #ra = 1
        
        # Calculate net solar shortwave radiation 
        rns = (1 - Lib.ALBEDO) * rs
        
        # Rso
        rso = Lib.rso(ra, elevation)
        
        # cloudness factor
        f = Lib.cloudness_factor(rs, rso, Lib.solar_altitude_angle(lat, doy, hod))
        
        rnl = f * epsilon_net * Lib.stephan_boltzmann(ta_c)
      
        rn = (0.77 * rns) - rnl
        
        if reference_crop == 'grass':
            crop_dependent_factor = 37
            if rn > 0:
                g = 0.1 * rn
                # Bulk surface resistance and aerodynamic resistance coefficient
                CD = 0.24 
            else:
                g = 0.5 * rn
                # Bulk surface resistance and aerodynamic resistance coefficient
                CD = 0.96 
        elif reference_crop == 'alfalfa':
            crop_dependent_factor = 66
            if rn > 0:
                g = 0.01 * rn
                # Bulk surface resistance and aerodynamic resistance coefficient
                CD = 0.25 
            else:
                g = 0.2 * rn
                # Bulk surface resistance and aerodynamic resistance coefficient
                CD = 1.7
            
            
        # decompose et0 to two terms to facilitate the calculation
        
        radiation = delta * (rn - g)
        
        denominator = delta + (gamma * (1 + (CD * u2)))
        
        radiation_term =(radiation) / (denominator * lambda_heat)
        
        # Aerodynamic Term
        aerodynamic_term = (gamma * ((crop_dependent_factor) / (ta_k)) * u2 * (es - ea)) / denominator
        
        
        et0 = radiation_term + aerodynamic_term
            
        # output result
        return et0
    
    @staticmethod
    def et0_penman_monteith_daily_v2(
        row,
        ):
        # input variables
        # T = 25.0  # air temperature in degrees Celsius
        # RH = 60.0  # relative humidity in percent
        # u2 = 2.0  # wind speed at 2 m height in m/s
        # Rs = 15.0  # incoming solar radiation in MJ/m2/day
        # lat = 35.0  # latitude in degrees
        G = 0
        
        ta_mean_c, rs_daily, rh_mean, ws_mean, lat, elevation, doy =  row['ta_mean'], row['rs_daily'], row['rh_mean'], row['ws_mean'], row['lat'], row['elevation'], row['doy']
        
        ta_mean_k = ta_mean_c + 273.16  # air temperature in Kelvin
        
        lambda_heat = Lib.latent_heat_of_vaporization(ta_mean_c)
        
        # saturation vapor pressure in kPa
        es = Lib.saturation_vapor_pressure(ta_mean_c)
        
        # actual vapor pressure in kPa
        ea = Lib.actual_vapor_pressure(ta_mean_c, rh_mean)
        
        epsilon_net = 0.34 - (0.14 * math.sqrt(ea))
        
        # slope of the vapor pressure curve in kPa/K
        delta = Lib.slope_of_saturation_vapor_pressure(ta_mean_c)
        
        # psychrometric constant in kPa/K
        gamma = Lib.psychrometric_constant(elevation, ta_mean_c)
        
        # Calculate extraterrestrial radiation
        ra = Lib.extraterrestrial_radiation(lat, doy)
        
        # Calculate net solar shortwave radiation 
        rns = (1 - Lib.ALBEDO) * rs_daily
        
        # Rso
        rso = Lib.rso(ra, elevation)
        
        # cloudness factor
        f = Lib.cloudness_factor(rs_daily, rso)
        
        rnl = f * epsilon_net * Lib.stephan_boltzmann(ta_mean_c, 'd')
      
        rn = (0.77 * rns) - rnl
        
        
        crop_dependent_factor = 37
        if rn > 0:
            # Bulk surface resistance and aerodynamic resistance coefficient
            CD = 0.24 
        else:
            # Bulk surface resistance and aerodynamic resistance coefficient
            CD = 0.96 
        
        # decompose et0 to two terms to facilitate the calculation
        
        radiation = delta * (rn - G)
        
        denominator = delta + (gamma * (1 + (CD * ws_mean)))
        
        radiation_term =(radiation) / (denominator * lambda_heat)
        
        # Aerodynamic Term
        aerodynamic_term = (gamma * ((crop_dependent_factor) / (ta_mean_k)) * ws_mean * (es - ea)) / denominator
        
        
        et0 = radiation_term + aerodynamic_term
            
        # output result
        return et0
    
    @staticmethod
    def psychrometric_constant(elevation, ta_c):
        """
        Calculate the psychrometric constant for a given altitude.

        Parameters:
        altitude (float): Altitude above sea level in meters.

        Returns:
        float: Psychrometric constant in kPa/°C.
        """
        
        lambda_v = Lib.latent_heat_of_vaporization(ta_c)  # Latent heat of vaporization (MJ/kg)
        
        # Calculate atmospheric pressure based on altitude
        p = Lib.pressure(elevation)
        
        # Calculate psychrometric constant
        gamma = (Lib.CP * p) / (Lib.EPSILON * lambda_v)
        
        return gamma
    
    @staticmethod
    def solar_altitude_angle(latitude, doy, hod):
        """
        Calculate the solar altitude angle based on latitude, day of the year, and local solar time.

        Parameters:
        - latitude: float, latitude of the observer in degrees
        - day_of_year: int, day of the year (1 through 365 or 366)
        - local_solar_time: float, local solar time in hours (solar noon is 12.0)

        Returns:
        - solar_altitude: float, solar altitude angle in degrees
        """
        # Convert latitude to radians
        latitude_rad = math.radians(latitude)

        # Calculate solar declination
        declination = 23.45 * math.sin(math.radians((360 / 365) * (doy - 81)))

        # Convert declination to radians
        declination_rad = math.radians(declination)

        # Calculate the hour angle
        hour_angle = 15 * (hod - 12)  # degrees from solar noon
        hour_angle_rad = math.radians(hour_angle)

        # Calculate the solar altitude angle
        sin_alpha = math.sin(latitude_rad) * math.sin(declination_rad) + \
                    math.cos(latitude_rad) * math.cos(declination_rad) * math.cos(hour_angle_rad)

        # Arcsine to get the angle in radians and then convert to degrees
        solar_altitude_rad = math.asin(sin_alpha)
        solar_altitude_degrees = math.degrees(solar_altitude_rad)

        return solar_altitude_degrees
    
    @staticmethod
    def pressure(z):
        ''' Calculates the barometric pressure above sea level.

        Parameters
        ----------
        z: float
            height above sea level (m).

        Returns
        -------
        p: float
            air pressure (Kpa).'''
            
        P0 = 101.325  # Standard atmospheric pressure at sea level in kPa
        L = 0.0065    # Standard lapse rate in °C/m
        p = P0 * (((293 - (L * z)) / (293)) ** 5.26)

        return p
    
    def latent_heat_of_vaporization(ta_c):
        """
        Estimate the latent heat of vaporization of water as a function of temperature, in MJ/kg.
        
        Parameters:
        - temp_celsius: float, temperature in degrees Celsius
        
        Returns:
        - lambda_v: float, latent heat of vaporization in MJ/kg
        """
        # Constants for water vaporization (values in J/g)
        # This approximation assumes a linear decrease from 2501.3 J/g at 0°C to 2264.7 J/g at 100°C
        
        # Adjust latent heat based on temperature
        lambda_v = 2.501 - (0.002361 * ta_c)
        return lambda_v
    
    @staticmethod
    def density_of_water(t_c):
        """
        density of air-free water ata pressure of 101.325kPa
        :param t_c: temperature in cellsius
        :return:
        density of water (kg m-3)
        """
        rho_w = (999.83952 + 16.945176 * t_c - 7.9870401e-3 * t_c**2
                - 46.170461e-6 * t_c**3 + 105.56302e-9 * t_c**4
                - 280.54253e-12 * t_c**5) / (1 + 16.897850e-3 * t_c)

        return rho_w
    
    @staticmethod
    def flux_2_evapotranspiration(flux, t_c=20, time_domain=1):
        '''Converts heat flux units (W m-2) to evaporation rates (mm time-1) to a given temporal window

        Parameters
        ----------
        flux : float or numpy array
            heat flux value to be converted,
            usually refers to latent heat flux LE to be converted to ET
        t_c : float or numpy array
            environmental temperature in Kelvin. Default=20 Celsius
        time_domain : float
            Temporal window in hours. Default 1 hour (mm h-1)

        Returns
        -------
        et : float or numpy array
            evaporation rate at the time_domain. Default mm h-1
        '''
        # Calculate latent heat of vaporization
        lambda_ = Lib.latent_heat_of_vaporization(t_c) * 10e6  # J kg-1
        # Density of water
        rho_w = Lib.density_of_water(t_c)  # kg m-3
        et = flux / (rho_w * lambda_)  # m s-1
        # Convert instantaneous rate to the time_domain rate
        et = et * 1e3 * time_domain * 3600.  # mm
        return et
    
    @staticmethod
    def saturation_vapor_pressure(ta_c):
        """
        Calculate saturation vapor pressure (es) in kPa given temperature (T) in Celsius
        
        """
        # Calculate saturation vapor pressure (es) using Magnus-Tetens formula
        es = 0.6108 * np.exp((17.27 * ta_c) / (ta_c + 237.3))
        return es
    
    @staticmethod
    def actual_vapor_pressure(ta_c, rh):
        """
        Calculate actual vapor pressure (ea) in kPa given temperature (T) in Celsius
        and relative humidity (RH) as a percentage.
        """
        
        ea = (rh / 100) * Lib.saturation_vapor_pressure(ta_c)
        return ea
    
    @staticmethod
    def stephan_boltzmann(t_c, freq='h'):
        '''Calculates the total energy radiated by a blackbody.

        Parameters
        ----------
        t_c: float
            body temperature (Celsius)

        Returns
        -------
         : float
            Emitted radiance (MJ m-2)'''
        
        t_k = t_c + 273.15
            
        if freq == 'h':
            # Stephan Boltzmann constant (MJ m-2 K-4)
            SB = 2.04e-10
        elif freq == 'd':
            SB = 4.903e-9 # Stefan-Boltzmann constant in MJ/K4/m2/day
            
        return SB * (t_k ** 4)
    
    def estimate_r_li(ta_c, ts_c):
        """
        Calculate actual vapor pressure (e) given temperature (T) in Celsius
        and relative humidity (RH) as a percentage.
        """
        
        r_li = f * self.stephan_boltzmann(ts_c)
        
        return r_li
    
    @staticmethod
    def cloudness_factor(rso, rs, solar_alt_angle):
        """
        Calculate actual vapor pressure (e) given temperature (T) in Celsius
        and relative humidity (RH) as a percentage.
        """
        
        if solar_alt_angle > 10:
            kt = rs / rso if rso > 0 else 0  # Avoid division by zero
            #kt = rs / rso
            f = (1.35 * kt) - 0.35
        
        elif solar_alt_angle <= 10:
            f = -1
        
        if f < 0:
            f = 0.595
        elif f > 1:
            f = 1
        
        return f
    
    @staticmethod
    def rso(ra, elevation):
        """
        Calculate clear-sky solar radiation based on extraterrestrial radiation and altitude.
        
        Parameters:
        - Ra: float, extraterrestrial radiation in MJ/m²/day
        - altitude: float, elevation above sea level in meters
        
        Returns:
        - Rso: float, clear-sky solar radiation in MJ/m²/day
        """
        rso = (0.75 + (2e-5 * elevation)) * ra
        return rso
    
    @staticmethod
    def inverse_relative_distance_factor(doy):
        """
        Calculate the inverse relative distance factor (dr) for Earth-Sun based on the day of the year.
        
        Parameters:
        - day_of_year: int, the day of the year (1 to 365 or 366 for a leap year)
        
        Returns:
        - dr: float, the inverse relative distance factor (dimensionless)
        
        Description:
        This function uses the cosine function to calculate the Earth-Sun distance variation effect.
        """
        return 1 + (0.033 * np.cos((2 * Lib.PI * doy) / 365))
    
    @staticmethod
    def net_longwave_radiation(ta_c, rh, rs, rso, epsilon=0.95):
        """
        Calculate the net longwave radiation, adjusting sky temperature based on empirical methods.
        
        Parameters:
        Ta (float): Air temperature in degrees Celsius.
        rh (float): Relative humidity in percent.
        Rs (float): Actual solar radiation in W/m2.
        Rso (float): Clear sky solar radiation in W/m2.
        epsilon (float): Emissivity of the surface (default 0.95).

        Returns:
        float: Net longwave radiation in W/m2.
        """
        sigma = 5.67e-8  # Stefan-Boltzmann constant in W/m2/K4
        ta_k = ta_c + 273.15  # Convert air temperature from Celsius to Kelvin

        # Calculate actual vapor pressure
        ea = 0.6108 * math.exp((17.27 * ta_c) / (ta_c + 237.3)) * (rh / 100)

        # Adjust sky temperature based on emissivity and air temperature
        sky_emissivity = 0.787 + 0.764 * math.log10(ea)
        Tsky_k = sky_emissivity * ta_k

        # Surface temperature approximated by air temperature (adjust if necessary)
        ts_k = ta_k
        
        # Estimate effective sky temperature
        # Clearness index
        kt = rs / rso if rso > 0 else 0  # Avoid division by zero
        # Calculate the net longwave radiation
        rn_l = sigma * (Tsky_k**4 - ts_k**4) * epsilon * ((1.35 * kt) - 0.35)

        return rn_l
    
    @staticmethod
    def et0_hargreaves_samani(row, c=0.0023, a=17.8, b=0.5):
        ta_mean, ta_max, ta_min, lat, doy =  row['ta_mean'], row['ta_max'], row['ta_min'], row['lat'], row['doy']
        
        ra = Lib.extraterrestrial_radiation_daily(lat, doy)
        
        # convert ra from MJ/m2/day to mm/day
        ra *= 0.408
        
        temperature_range = ta_max - ta_min
        
        # et0 = 0.0023 * (ta_mean + 17.8) * ((ta_max - ta_min) ** 0.5) * 0.408 * ra
        
        et0 = c * (ta_mean + a) * (temperature_range ** b) * ra

        return et0

    @staticmethod
    def get_elevation(lat, lon):
        """
        Returns the elevation (in meters) and latitude (in degrees) for a given set of coordinates.
        Uses the Open Elevation API (https://open-elevation.com/) to obtain the elevation information.
        """
        # 'https://api.open-elevation.com/api/v1/lookup?locations=10,10|20,20|41.161758,-8.583933'
        url = f'https://api.opentopodata.org/v1/aster30m?locations={lat},{lon}'
        response = requests.get(url)
        print(response.json())
        data = response.json()
        elevation = data['results'][0]['elevation']
        #latitude = data['results'][0]['latitude']
        return elevation
    
    @staticmethod
    def logarithmic_wind_profile(u, v, z_source=10, z_target=2, z0=0.03):
        """
        Calculate wind speed at 2 meters given wind speed components at 10 meters.
        
        Parameters:
        u10 (float): Wind speed component in the u-direction at 10 meters (m/s).
        v10 (float): Wind speed component in the v-direction at 10 meters (m/s).
        z_source (float): Source height where wind speed is measured (default is 10 meters).
        z_target (float): Target height where wind speed is to be estimated (default is 2 meters).
        z0 (float): Roughness length (default is 0.03 meters, adjust based on terrain).
                Typical values for roughness length:
                - Short grass: 0.01 - 0.03 meters
                - Tall grass: 0.1 - 0.2 meters
                - Crops: 0.05 - 0.25 meters (depending on height and density)
                - Shrubs: 0.1 - 0.5 meters
                - Forests: 1.0 - 2.0 meters (varies with tree height and density)
                - Urban areas: 0.5 - 1.5 meters (depends on building density and height)
        
        Returns:
        float: Estimated wind speed at 2 meters (m/s).
        """
        # Calculate wind speed at the source height (10 meters)
        wind_speed_source = math.sqrt(u**2 + v**2)
        
        # Calculate wind speed at the target height (2 meters) using the logarithmic wind profile
        wind_speed_target = wind_speed_source * (math.log(z_target / z0) / math.log(z_source / z0))
        
        return wind_speed_target
    
    @staticmethod    
    def relative_humidity_magnus(ta_c, dew_point_c):
        """
        Estimate relative humidity given dew point and air temperature using the Magnus formula.
        
        :param ta_c: Air temperature in Celsius
        :param dew_point_c: Dew point temperature in Celsius
        :return: Relative humidity in percentage
        """
        # Constants for the formula
        a = 17.62
        b = 243.12
        
        # Calculate alpha for dew point
        alpha_dp = (a * dew_point_c) / (b + dew_point_c)
        
        # Calculate alpha for temperature
        alpha_t = (a * ta_c) / (b + ta_c)
        
        # Calculate relative humidity
        rh = 100 * (math.exp(alpha_dp) / math.exp(alpha_t))
        
        return rh
    
    @staticmethod
    def slope_saturation_vapor_pressure_curve(t_c, method='standard'):
        """
        Calculate the slope of the saturation vapor pressure curve at a given temperature.
        
        Parameters:
        - temp_celsius: float, temperature in degrees Celsius
        
        Returns:
        - delta: float, slope of the vapor pressure curve in kPa/°C
        """
        # Calculate saturation vapor pressure at the current temperature
        es = Lib.saturation_vapor_pressure(t_c)
        
        # Calculate the slope of the vapor pressure curve
        delta = (4098 * es) / ((t_c + 237.3) ** 2)
        return delta
    
    @staticmethod
    def extraterrestrial_radiation_hourly_v3(doy, lat, lon, hod, tz_offset):
        """
        Calculate hourly extraterrestrial radiation (Ra) using Duffie and Beckman's approach and G_sc in MJ/m²/min.
        
        Parameters:
        - day_of_year: int, day of the year (1-365 or 366)
        - latitude: float, latitude in degrees
        - longitude: float, local longitude in degrees
        - standard_meridian: float, longitude of the standard time meridian for the time zone
        - local_time: float, local standard time hour (24-hour format)
        
        Returns:
        - Ra_h: float, hourly extraterrestrial radiation in MJ/m^2
        """
        # Convert latitude and longitude from degrees to radians
        latitude_rad = math.radians(lat)
        
        # Solar declination in radians
        delta = Lib.solar_declination(doy)
        
        # Adjust local time to solar time
        half_hour_before_solar_time = hod - 0.5 
        omega = Lib.solar_time_angle(Lib.solar_time(half_hour_before_solar_time, lat, lon, doy, tz_offset))
        
        # Calculate solar time angles at the start and end of the hour
        omega_1 = omega - (0.5 * (Lib.PI/12))
        omega_2 = omega + (0.5 * (Lib.PI/12))
        
        
        # Hourly extraterrestrial radiation calculation
        ra_h = ((60) / Lib.PI) * Lib.SOLAR_CONSTANT_MJ_MIN * Lib.inverse_relative_distance_factor(doy) * ((omega_2 - omega_1) * math.sin(latitude_rad) * math.sin(delta) + math.cos(latitude_rad) * math.cos(delta) * (math.sin(omega_2) - math.sin(omega_1)))
        
        return ra_h
    
    @staticmethod
    def time_zone_offset_current_location():
        local_time = datetime.now(pytz.timezone('UTC'))
        local_time = local_time.astimezone()  # Converts to local time zone
        offset = local_time.utcoffset().total_seconds() / 3600
        return offset
    
    def time_zone_offset(lat, lon):
       # Replace '<USERNAME>' with your GeoNames username
        username = 'elhachimi.ch'
        
        print(geocoder.location(location=f"{lat}+{lon}"))
        print('okkkkkkkkkkkkkk')
        # Fetch geonames details using the coordinates
        g = geocoder.geonames([lat, lon], key=username, method='findNearby')

        # Check if the geocode request was successful
        if g.ok:
            geoname_id = g.geonames_id
            print(f"GeoName ID for coordinates ({lat}, {lon}): {geoname_id}")
        else:
            print("Failed to retrieve GeoName ID for coordinates")

        # Fetch detailed information using the GeoNames ID
        g = geocoder.geonames(geoname_id, method='details', key=username)

        # Extract relevant information
        if g.ok:
            timezone_id = g.json.get('timezone', {}).get('timeZoneId')
            raw_offset = g.json.get('timezone', {}).get('rawOffset')
            dst_offset = g.json.get('timezone', {}).get('dstOffset')

            print(f"TimeZone ID: {timezone_id}")
            print(f"Raw Offset: {raw_offset} hours")
            print(f"DST Offset: {dst_offset} hours")
        else:
            print("Failed to retrieve data")
    
    @staticmethod
    def standard_meridian(time_zone_offset):
        return 15 * time_zone_offset

    @staticmethod
    def solar_time(hod, lat, lon, doy, tz_offset):
        eot = Lib.equation_of_time(doy)
        solar_time = hod + (eot + 4 * (lon - Lib.standard_meridian(tz_offset))) / 60
        return solar_time
    
    def solar_time_angle(solar_time):
        """_summary_

        Args:
            solar_time (_type_): _description_

        Returns:
            omega: the solar time angle in radians
        """
        # 15 = PI/12
        return (Lib.PI * (solar_time - 12)) / 12
    
    @staticmethod
    def solar_time_angle_at_midpoint(hour, longitude, standard_meridian, equation_of_time):
        # Calculate the midpoint of the previous hour
        local_time_in_hours = hour - 0.5

        # Calculate solar time
        solar_time = local_time_in_hours + (4 * (standard_meridian - longitude) + equation_of_time) / 60.0

        # Calculate hour angle in degrees
        hour_angle_degrees = 15 * (solar_time - 12)

        # Convert hour angle to radians
        hour_angle_radians = math.radians(hour_angle_degrees)

        return hour_angle_radians
    
    @staticmethod
    def equation_of_time(doy):
        # Convert the day of the year to radians (angle B)
        B = (2 * Lib.PI * (doy - 81)) / 365 

        # Calculate the equation of time in minutes
        #eot = 9.87 * math.sin(2 * B) - 7.53 * math.cos(B) - 1.5 * math.sin(B)
        eot = 0.1645 * math.sin(2 * B) - 0.1255 * math.cos(B) - 0.025 * math.sin(B)

        return eot
        
    @staticmethod
    def extraterrestrial_radiation_hourly(doy, latitude, longitude, hod, standard_meridian):
        """
        Calculate hourly extraterrestrial radiation (Ra) using Duffie and Beckman's approach and G_sc in MJ/m²/min.
        
        Parameters:
        - day_of_year: int, day of the year (1-365 or 366)
        - latitude: float, latitude in degrees
        - longitude: float, local longitude in degrees
        - standard_meridian: float, longitude of the standard time meridian for the time zone
        - local_time: float, local standard time hour (24-hour format)
        
        Returns:
        - Ra_h: float, hourly extraterrestrial radiation in MJ/m^2
        """
        # Convert latitude and longitude from degrees to radians
        latitude_rad = math.radians(latitude)
        
        # Solar declination in radians
        delta = Lib.solar_declination(doy)
        
        # Equation of Time in minutes
        B = ((2 * Lib.PI) / 364) * (doy - 81)
        #B = math.radians(B)
        EOT = 0.1645 * math.sin(2 * B) - 0.1255 * math.cos(B) - 0.025 * math.sin(B)
        
        standard_meridian = -120
        # Adjust local time to solar time
        omega = (Lib.PI/12) * (((hod - 0.5) - ((4/60) * (longitude - standard_meridian) + EOT)) - 12)
        #omega = 5
        
        # Calculate solar time angles at the start and end of the hour
        omega_1 = omega - (0.5 * (Lib.PI/12))
        omega_2 = omega + (0.5 * (Lib.PI/12))
        omega_delta = omega_2 - omega_1
        
        ra_second_term = (omega_delta * math.sin(latitude_rad) * math.sin(delta) + math.cos(latitude_rad) * math.cos(delta) * (math.sin(omega_2) - math.sin(omega_1)))
        #ra_second_term = 0.01
        # Hourly extraterrestrial radiation calculation
        ra_h = ((12 * 60 * Lib.SOLAR_CONSTANT_MJ_MIN * Lib.inverse_relative_distance_factor(doy)) / Lib.PI) * ra_second_term
        
        return ra_h
    
    def extraterrestrial_radiation_hourly_v2(doy, latitude, longitude, hod, standard_meridian):
        """
        Calculate hourly extraterrestrial radiation (Ra) using Duffie and Beckman's approach and G_sc in MJ/m²/min.
        
        Parameters:
        - doy: int, day of the year (1-365 or 366)
        - latitude: float, latitude in degrees
        - longitude: float, local longitude in degrees
        - standard_meridian: float, longitude of the standard time meridian for the time zone
        - hod: float, local standard time hour (24-hour format)
        
        Returns:
        - Ra_h: float, hourly extraterrestrial radiation in MJ/m^2
        """
        # Convert latitude from degrees to radians
        latitude_rad = math.radians(latitude)
        
        # Solar declination in radians
        delta = Lib.solar_declination(doy)
        
        # Equation of Time in minutes
        B = ((2 * math.pi) / 364) * (doy - 81)
        EOT = 0.1645 * math.sin(2 * B) - 0.1255 * math.cos(B) - 0.025 * math.sin(B)
        
        # Adjust local time to solar time
        solar_time = hod + (4 * (longitude - standard_meridian) + EOT) / 60
        
        # Calculate the solar hour angle at the middle of the hour
        omega = (math.pi / 12) * (solar_time - 12)
        
        # Calculate the solar time angles at the start and end of the hour
        omega_1 = omega - (math.pi / 24)
        omega_2 = omega + (math.pi / 24)
        
        # Hourly extraterrestrial radiation calculation
        G_sc = 4.9212  # Solar constant in MJ/m^2/hr
        Ra_h = ((12 * 3600) / math.pi) * G_sc * Lib.inverse_relative_distance_factor(doy) * (
            (omega_2 - omega_1) * math.sin(latitude_rad) * math.sin(delta) +
            math.cos(latitude_rad) * math.cos(delta) * (math.sin(omega_2) - math.sin(omega_1))
        )
        
        return Ra_h
    
    @staticmethod
    def solar_declination(doy):
        """
        Calculate the solar declination in radians for a given day of the year using a precise trigonometric model.

        Parameters:
        - doy: int, day of the year (1 through 365 or 366)

        Returns:
        - declination: float, solar declination in radians
        """
        # Convert day of the year to radians within the sine function
        declination_radians = 0.409 * np.sin(((2 * Lib.PI * doy) / 365) - 1.39)

        return declination_radians
  
    @staticmethod
    def extraterrestrial_radiation_daily(lat, doy):
        """
        Calculate extraterrestrial radiation (Ra) for a given latitude and day of the year.

        Parameters:
        lat (float): Latitude in degrees. Positive for the northern hemisphere, negative for southern.
        doy (int): Day of the year (1 through 365 or 366).

        Returns:
        float: Extraterrestrial radiation in MJ/m^2/day.
        """
        
        lat_rad = np.radians(lat)
        
        # Calculate the inverse relative distance Earth-Sun (dr)
        dr = Lib.inverse_relative_distance_factor(doy)
        
        # Calculate the solar declination (δ):
        delta = Lib.solar_declination(doy)
        
        # Calculate the sunset hour angle
        omega = Lib.sunset_hour_angle(lat, delta)
        
        # Calculate the extraterrestrial radiation
        ra = ((24 * 60) / math.pi) * Lib.SOLAR_CONSTANT_MJ_MIN * dr * ((omega * np.sin(lat_rad) * np.sin(delta)) + (np.cos(lat_rad) * np.cos(delta) * np.sin(omega)))
        
        return ra
    
    @staticmethod
    def sunset_hour_angle(lat, declination):
        """
        Calculate the sunset hour angle in radians.

        Parameters:
        latitude (float): Latitude in decimal degrees.
        declination (float): Solar declination in radians.

        Returns:
        float: Sunset hour angle in radians.
        """
        # Convert latitude to radians
        lat_rad = np.radians(lat)
        
        # Calculate the sunset hour angle using the formula
        omega = np.arccos(-np.tan(lat_rad) * np.tan(declination))
        
        return omega
    
    @staticmethod
    def et0_priestley_taylor_daily(row, alpha=1.26):
        # input variables
        # T = 25.0  # air temperature in degrees Celsius
        # RH = 60.0  # relative humidity in percent
        # u2 = 2.0  # wind speed at 2 m height in m/s
        # Rs = 15.0  # incoming solar radiation in MJ/m2/day
        # lat = 35.0  # latitude in degrees
        
        #ta_mean, rs_mean, rh_mean, lat, elevation, doy =  row['ta_mean'], row['rs_mean'], row['rh_mean'], row['lat'], row['elevation'], row['doy']
        G = 0  # Soil heat flux density (MJ/m2/day)
        
        ta_max, ta_min, rh_max, rh_min, rs_mean, lat, elevation, doy =  row['ta_max'], row['ta_min'], row['rh_max'], row['rh_min'], row['rs_mean'], row['lat'], row['elevation'], row['doy']
        
        rs_mean *= 0.0864  # convert watts per square meter to megajoules per square meter 0.0288 = 60x60x8hours or 0.0864 for 24 hours

        ta_mean = (ta_max + ta_min) / 2
        ta_max_kelvin = ta_max + 273.16  # air temperature in Kelvin
        ta_min_kelvin = ta_min + 273.16  # air temperature in Kelvin
        
        # saturation vapor pressure in kPa
        es_max = 0.6108 * math.exp((17.27 * ta_max) / (ta_max + 237.3))
        es_min = 0.6108 * math.exp((17.27 * ta_min) / (ta_min + 237.3))
        
        # actual vapor pressure in kPa
        ea_max_term = es_max * (rh_min / 100)
        ea_min_term = es_min * (rh_max / 100)
        ea = (ea_max_term + ea_min_term) / 2
        
        # in the absence of rh_max and rh_min
        #ea = (rh_mean / 100) * es
        
        # when using equipement where errors in estimation rh min can be large or when rh data integrity are in doubt use only rh_max term
        #ea = ea_min_term  
        
        delta = Lib.slope_saturation_vapor_pressure_curve(ta_mean) # slope of the vapor pressure curve in kPa/K
        
        # psychrometric constant in kPa/K
        gamma = Lib.psychrometric_constant(elevation, ta_mean)
        
        
        # Calculate extraterrestrial radiation
        ra = Lib.extraterrestrial_radiation_daily(lat, doy)
        
        # Calculate clear sky solar radiation
        rso = (0.75 + (2e-5 * elevation)) * ra
        
        # Calculate net solar shortwave radiation 
        rns = (1 - Lib.ALBEDO) * rs_mean
        
        # Calculate net longwave radiation
        
        rnl = Lib.SIGMA * (((math.pow(ta_max_kelvin, 4) + math.pow(ta_min_kelvin, 4)) / 2) * (0.34 - (0.14 * math.sqrt(ea))) * ((1.35 * (rs_mean / rso)) - 0.35))
        
        # Calculate net radiation
        rn = rns - rnl
       
        et0 = (alpha * delta * (rn - G) * 0.408) / (delta + gamma)
            
        # output result
        return et0
    
    @staticmethod
    def net_emissivity_of_surface(ta_c, rh):
        
        ea = Lib.actual_vapor_pressure(ta_c, rh)
        
        epsilon_net = 0.34 - (0.14 * math.sqrt(ea))
        
        return epsilon_net
    
    @staticmethod
    def et0_priestley_taylor_daily_v2(row):
        """
        Calculate the reference evapotranspiration using the Priestley-Taylor method.

        Parameters:
        alpha (float): Empirical coefficient, typically around 1.26.
        Delta (float): Slope of the saturation vapor pressure curve at air temperature (kPa/°C).
        gamma (float): Psychrometric constant (kPa/°C).
        Rn (float): Net radiation at the crop surface (MJ/m²/day).
        G (float): Soil heat flux (MJ/m²/day), often assumed to be zero for daily calculations.

        Returns:
        float: Estimated ET0 in mm/day.
        """
        
        ta_c = row['ta_mean']
        
        seconds_per_day = 36000 # 43200 for 12 hours number of seconds in a day 86400 for 24 hours
        
        # Conversion from W/m² to kJ/m²/day
        rs_kj_per_m2 = (row['rs_mean'] * seconds_per_day) / 1000  # Convert joules to kilojoules
        
        #elevation = row['elevation']
        GHO = Lib.DENSITY_OF_WATER
        lambda_v = 2266
        DELTA = 4.95e-4
        
        if ta_c < 0:
            slope = 0.3405 * (math.exp(0.06642 * ta_c))
        else:
            slope = 0.3221 * (math.exp(0.0803 * (ta_c ** 0.8876)))
        
        et0 = ((1.3) / (lambda_v * GHO)) * ((slope)/(slope + DELTA)) * rs_kj_per_m2
        return et0 * 1000
    
    @staticmethod
    def et0_priestley_taylor_hourly(row, ta_column_name, rs_column_name):
        """
        Calculate the reference evapotranspiration using the Priestley-Taylor method.

        Parameters:
        alpha (float): Empirical coefficient, typically around 1.26.
        Delta (float): Slope of the saturation vapor pressure curve at air temperature (kPa/°C).
        gamma (float): Psychrometric constant (kPa/°C).
        Rn (float): Net radiation at the crop surface (MJ/m²/day).
        G (float): Soil heat flux (MJ/m²/day), often assumed to be zero for daily calculations.

        Returns:
        float: Estimated ET0 in mm/day.
        """
        
        ta_c = row[ta_column_name]
        
        seconds_per_day = 3600 # 43200 for 12 hours number of seconds in a day 86400 for 24 hours
        
        # Conversion from W/m² to kJ/m²/day
        rs_kj_per_m2 = (row[rs_column_name] * seconds_per_day) / 1000  # Convert joules to kilojoules
        
        #elevation = row['elevation']
        GHO = Lib.DENSITY_OF_WATER
        lambda_v = 2266
        DELTA = 4.95e-4
        
        
        if ta_c < 0:
            slope = 0.3405 * (math.exp(0.06642 * ta_c))
        else:
            slope = 0.3221 * (math.exp(0.0803 * (ta_c ** 0.8876)))
        
        et0 = ((1.3) / (lambda_v * GHO)) * ((slope)/(slope + DELTA)) * rs_kj_per_m2
        return et0 * 1000
    
    @staticmethod
    def et0_schendel(row):
        """
        Calculate the reference evapotranspiration using the Priestley-Taylor method.

        Parameters:
        alpha (float): Empirical coefficient, typically around 1.26.
        Delta (float): Slope of the saturation vapor pressure curve at air temperature (kPa/°C).
        gamma (float): Psychrometric constant (kPa/°C).
        Rn (float): Net radiation at the crop surface (MJ/m²/day).
        G (float): Soil heat flux (MJ/m²/day), often assumed to be zero for daily calculations.

        Returns:
        float: Estimated ET0 in mm/day.
        """
        
        ta_mean_c = row['ta_mean']
        rh_mean = row['rh_mean']
        
        
        et0 = 16 * (ta_mean_c / rh_mean)
        return et0
    
    @staticmethod
    def et0_abtew(row, k1=0.53):
        """
        Calculate the reference evapotranspiration using the Priestley-Taylor method.

        Parameters:
        alpha (float): Empirical coefficient, typically around 1.26.
        Delta (float): Slope of the saturation vapor pressure curve at air temperature (kPa/°C).
        gamma (float): Psychrometric constant (kPa/°C).
        Rn (float): Net radiation at the crop surface (MJ/m²/day).
        G (float): Soil heat flux (MJ/m²/day), often assumed to be zero for daily calculations.

        Returns:
        float: Estimated ET0 in mm/day.
        """
        
        rs_mean = row['rs_mean']
        
        rs_mean *= 0.0864  # convert watts per square meter to megajoules per square meter 0.0288 = 60x60x8hours or 0.0864 for 24 hours
        
        lambda_v = Lib.LATENT_HEAT_OF_VAPORIZATION
        K1 = k1
        
        
        et0 = (K1 * rs_mean) / lambda_v
        return et0
    
    @staticmethod
    def et0_turc(row):
        """
        Calculate the reference evapotranspiration using the Priestley-Taylor method.

        Parameters:
        alpha (float): Empirical coefficient, typically around 1.26.
        Delta (float): Slope of the saturation vapor pressure curve at air temperature (kPa/°C).
        gamma (float): Psychrometric constant (kPa/°C).
        Rn (float): Net radiation at the crop surface (MJ/m²/day).
        G (float): Soil heat flux (MJ/m²/day), often assumed to be zero for daily calculations.

        Returns:
        float: Estimated ET0 in mm/day.
        """
        
        LAMBDA = 2.45
        ta_mean_c = row['ta_mean']
        rh_mean = row['rh_mean'] / 100
        rs_mean = row['rs_mean']
        
        seconds_per_day = 43200 # 43200 for 12 hours number of seconds in a day 86400 for 24 hours
        
        # Conversion from W/m² to MJ/m²/day
        rs_mj_per_m2 = (rs_mean * seconds_per_day) / 1000000  # Convert joules to Megajoules
        
        if ta_mean_c < 0:
            et0 = 0
        elif ta_mean_c > 0 and rh_mean < 0.5:
            et0 = 0.013 * ( (ta_mean_c) / (ta_mean_c + 15)) * ((23.89 * rs_mj_per_m2) + 50) * (1 + ( (50 - rh_mean) / 70))
        elif ta_mean_c > 0 and rh_mean > 0.5:
            et0 = 0.013 * ( (ta_mean_c) / (ta_mean_c + 15)) * ((23.89 * rs_mj_per_m2) + 50)
            #et0 = 0.013 * ( (ta_mean_c) / (ta_mean_c + 15)) * (((23.88 * rs_kj_per_m2) + 50) / LAMBDA)
            
        return et0
    
    @staticmethod
    def et0_mahringer(row):
        """
        Calculate the reference evapotranspiration using the Priestley-Taylor method.

        Parameters:
        alpha (float): Empirical coefficient, typically around 1.26.
        Delta (float): Slope of the saturation vapor pressure curve at air temperature (kPa/°C).
        gamma (float): Psychrometric constant (kPa/°C).
        Rn (float): Net radiation at the crop surface (MJ/m²/day).
        G (float): Soil heat flux (MJ/m²/day), often assumed to be zero for daily calculations.

        Returns:
        float: Estimated ET0 in mm/day.
        """
        
        LAMBDA = 2.45
        ws_mean = row['ws_mean']
        rh_mean = row['rh_mean'] / 100
        ta_mean = row['ta_mean']
        
        seconds_per_day = 43200 # 43200 for 12 hours number of seconds in a day 86400 for 24 hours
        
        et0 = (0.15072 * math.sqrt(3.6 *ws_mean) + 0.062 * ws_mean) * (Lib.saturation_vapor_pressure(ta_mean) - Lib.actual_vapor_pressure(ta_mean, rh_mean))
        return et0
    
    @staticmethod
    def et0_makkink(row, c1=0.61, c2=0.12):
        """
        Calculate the reference evapotranspiration using the Priestley-Taylor method.

        Parameters:
        alpha (float): Empirical coefficient, typically around 1.26.
        Delta (float): Slope of the saturation vapor pressure curve at air temperature (kPa/°C).
        gamma (float): Psychrometric constant (kPa/°C).
        Rn (float): Net radiation at the crop surface (MJ/m²/day).
        G (float): Soil heat flux (MJ/m²/day), often assumed to be zero for daily calculations.

        Returns:
        float: Estimated ET0 in mm/day.
        """
        
        
        rs_mean = row['rs_mean']
        ta_mean = row['ta_mean']
        elevation = row['elevation']
        
        delta = Lib.slope_saturation_vapor_pressure_curve(ta_mean)
        gama = Lib.psychrometric_constant(elevation, ta_mean)
        lam = Lib.latent_heat_of_vaporization(ta_mean)
        
        # convert units
        rs_mean *= 0.0864  # convert watts per square meter to megajoules per square meter 0.0288 = 60x60x8hours or 0.0864 for 24 hours
        
        et0 = ((c1 * delta * rs_mean) / ((delta + gama) * lam)) - c2
        return et0

    @staticmethod
    def temperature_seasonality_index(temperatures):
        return np.std(temperatures)

    @staticmethod
    def precipitation_seasonality_index(precipitations):
        mean_precip = np.mean(precipitations)
        return (np.std(precipitations) / mean_precip) * 100

    @staticmethod
    def thornthwaite_moisture_index(annual_precip, annual_pet):
        return (100 * (annual_precip - annual_pet)) / annual_pet

    @staticmethod
    def aridity_index(annual_precip, annual_pet):
        return annual_precip / annual_pet

    @staticmethod
    def classify_koppen_geiger(temps, precips, annual_precip, annual_temp):
        if all(temp > 18 for temp in temps):
            if min(precips) >= 60:
                return 'Af - Tropical Rainforest'
            elif min(precips) < 60 and annual_precip >= 25 * (100 - (100 / (np.std(precips) / np.mean(precips)))):
                return 'Am - Tropical Monsoon'
            else:
                return 'Aw - Tropical Savanna'
        elif annual_precip < 10 * annual_temp:
            if annual_precip < 5 * annual_temp:
                return 'BW - Arid Desert'
            else:
                return 'BS - Arid Steppe'
        elif min(temps) >= 0 and max(temps) < 18:
            if max(temps) > 22:
                if min(precips[3:8]) < 40:
                    return 'Csa - Mediterranean Hot Summer'
                else:
                    return 'Cfa - Humid Subtropical'
            else:
                if min(precips[3:8]) < 40:
                    return 'Csb - Mediterranean Warm Summer'
                else:
                    return 'Cfb - Oceanic Climate'
        elif min(temps) < 0:
            if max(temps) > 22:
                if min(precips[3:8]) < 40:
                    return 'Dsa - Mediterranean Hot Summer Continental'
                else:
                    return 'Dfa - Humid Continental Hot Summer'
            else:
                if min(precips[3:8]) < 40:
                    return 'Dsb - Mediterranean Warm Summer Continental'
                else:
                    return 'Dfb - Humid Continental Warm Summer'
        else:
            if max(temps) < 10:
                if max(temps) > 0:
                    return 'ET - Tundra'
                else:
                    return 'EF - Ice Cap'