Implement weather calculations in the service

2026-01-14 01:25:38 -05:00 · 2020-07-17 12:31:56 +00:00
parent 4c8649fe31
commit ec0b3c9eb1
10 changed files with 263 additions and 77 deletions
--- a/Weather/Service/Models/WeatherUpdate.cs
+++ b/Weather/Service/Models/WeatherUpdate.cs
@@ -0,0 +1,114 @@
+using System.Linq;
+using ChrisKaczor.HomeMonitor.Weather.Models;
+using ChrisKaczor.HomeMonitor.Weather.Service.Data;
+using DecimalMath;
+using JetBrains.Annotations;
+using MathNet.Numerics;
+
+namespace ChrisKaczor.HomeMonitor.Weather.Service.Models
+{
+    [PublicAPI]
+    public class WeatherUpdate : WeatherMessage
+    {
+        private Database _database;
+
+        public decimal? WindChill { get; set; }
+
+        public decimal? HeatIndex { get; set; }
+
+        public decimal DewPoint { get; set; }
+
+        public decimal PressureTrend { get; set; }
+
+        public WeatherUpdate(WeatherMessage weatherMessage, Database database)
+        {
+            _database = database;
+
+            Type = weatherMessage.Type;
+            Message = weatherMessage.Message;
+            Timestamp = weatherMessage.Timestamp;
+            WindDirection = weatherMessage.WindDirection;
+            WindSpeed = weatherMessage.WindSpeed;
+            Humidity = weatherMessage.Humidity;
+            HumidityTemperature = weatherMessage.HumidityTemperature;
+            Rain = weatherMessage.Rain;
+            Pressure = weatherMessage.Pressure;
+            PressureTemperature = weatherMessage.PressureTemperature;
+            BatteryLevel = weatherMessage.BatteryLevel;
+            LightLevel = weatherMessage.LightLevel;
+            Latitude = weatherMessage.Latitude;
+            Longitude = weatherMessage.Longitude;
+            Altitude = weatherMessage.Altitude;
+            SatelliteCount = weatherMessage.SatelliteCount;
+            GpsTimestamp = weatherMessage.GpsTimestamp;
+
+            HeatIndex = CalculateHeatIndex();
+            WindChill = CalculateWindChill();
+            DewPoint = CalculateDewPoint();
+            PressureTrend = CalculatePressureTrend();
+
+            Rain = database.GetReadingValueSum(WeatherValueType.Rain, Timestamp.AddHours(-1), Timestamp).Result;
+        }
+
+        private decimal CalculatePressureTrend()
+        {
+            var pressureData = _database.GetReadingValueHistory(WeatherValueType.Pressure, Timestamp.AddHours(-3), Timestamp).Result;
+
+            var xData = pressureData.Select(p => (double)p.Timestamp.ToUnixTimeSeconds()).ToArray();
+            var yData = pressureData.Select(p => (double)p.Value / 100.0).ToArray();
+
+            var lineFunction = Fit.LineFunc(xData, yData);
+
+            var difference = (decimal) (lineFunction(yData.Length - 1) - lineFunction(0));
+
+            return difference;
+        }
+
+        private decimal? CalculateHeatIndex()
+        {
+            var temperature = PressureTemperature;
+            var humidity = Humidity;
+
+            if (temperature.IsBetween(80, 100) && humidity.IsBetween(40, 100))
+            {
+                var heatIndex = -42.379m + 2.04901523m * temperature + 10.14333127m * humidity - .22475541m * temperature * humidity - .00683783m * temperature * temperature -
+                                .05481717m * humidity * humidity + .00122874m * temperature * temperature * humidity + .00085282m * temperature * humidity * humidity -
+                                .00000199m * temperature * temperature * humidity * humidity;
+
+                return heatIndex;
+            }
+
+            return null;
+        }
+
+        private decimal? CalculateWindChill()
+        {
+            var temperatureInF = PressureTemperature;
+            var windSpeedInMph = WindSpeed;
+
+            if (temperatureInF.IsBetween(-45, 45) && windSpeedInMph.IsBetween(3, 60))
+            {
+                var windChill = 35.74m + 0.6215m * temperatureInF - 35.75m * DecimalEx.Pow(windSpeedInMph, 0.16m) + 0.4275m * temperatureInF * DecimalEx.Pow(windSpeedInMph, 0.16m);
+
+                return windChill;
+            }
+
+            return null;
+        }
+
+        private decimal CalculateDewPoint()
+        {
+            var relativeHumidity = Humidity;
+            var temperatureInF = PressureTemperature;
+
+            var temperatureInC = (temperatureInF - 32.0m) * 5.0m / 9.0m;
+
+            var vaporPressure = relativeHumidity * 0.01m * 6.112m * DecimalEx.Exp(17.62m * temperatureInC / (temperatureInC + 243.12m));
+            var numerator = 243.12m * DecimalEx.Log(vaporPressure) - 440.1m;
+            var denominator = 19.43m - DecimalEx.Log(vaporPressure);
+            var dewPointInC = numerator / denominator;
+
+            return dewPointInC * 9.0m / 5.0m + 32.0m;
+        }
+    }
+}