public static double Calculate(double elevation, Atmosphere atmosphere)
{
double temperature = atmosphere.Temperature;
double pressure = atmosphere.Pressure;
double humidity = atmosphere.Humidity;
// Process the input values
double tf = 1.0*temperature; // temperature, deg F
humidity = 1.0*humidity; // relative humidity, %
pressure = 1.0*pressure; // altimeter setting, in-Hg
double z = 1.0*elevation; // geometric elevation, feet
// Convert to metric units
const double MB_PER_IN = 33.86389;
const double M_PER_FT = 0.304800;
double tc = (5.0/9.0)*(tf - 32);
double altsetmb = pressure*MB_PER_IN;
double zm = z*M_PER_FT;
// Calculate the vapor pressures (mb) given the ambient temperature (c) and relative humidity (c)
double esmb = CalcVaporPressureWobus(tc);
double emb = esmb*humidity/100;
// Calculate geopotential altitude H (m) from geometric altitude (m) Z
double hm = CalcH(zm);
// Calculate the absolute pressure given the altimeter setting(mb) and geopotential elevation(meters)
double actpressmb = CalcAs2Press(altsetmb, hm);
// Calculate the air density (kg/m3) from absolute pressure (mb) vapor pressure (mb) and temp (c)
double density = CalcDensity(actpressmb, emb, tc);
// double relden = 100*(density/1.225);
// Calculate the geopotential altitude (m) in ISA with that same density (kg/m3)
double densaltm = CalcAltitude(density);
// Calculate geometric altitude Z (m) from geopotential altitude (m) H
double densaltzm = CalcZ(densaltm);
// Convert Units for output
// const double IN_PER_MB = (1/33.86389);
// double actpress = actpressmb*IN_PER_MB;
const double FT_PER_M = (1/0.304800);
double densalt = densaltzm*FT_PER_M;
return RoundNum(densalt, 0);
}
public Conditions GetConditions()
{
var doc = XDocument.Load(uri.AbsoluteUri);
doc.Save("results.xml");
const string WEATHER = "{http://xml.weather.yahoo.com/ns/rss/1.0}";
const string GEO = "{http://www.w3.org/2003/01/geo/wgs84_pos#}";
const string ATMOSPHERE = "{0}atmosphere";
const string CONDITION = "{0}condition";
const string LATITUDE = "{0}lat";
const string LONGITUDE = "{0}long";
var atmosphere = doc.Descendants(string.Format(ATMOSPHERE, WEATHER)).FirstOrDefault();
var hAttribute = atmosphere.Attribute("humidity");
var pAttribute = atmosphere.Attribute("pressure");
if (hAttribute == null || pAttribute == null)
{
return Conditions.Empty;
}
var h = double.Parse(hAttribute.Value);
var p = double.Parse(pAttribute.Value);
XElement condition = doc.Descendants(string.Format(CONDITION, WEATHER)).FirstOrDefault();
var tAttribute = condition.Attribute("temp");
if (tAttribute == null)
{
return Conditions.Empty;
}
var t = double.Parse(tAttribute.Value);
XElement latitude = doc.Descendants(string.Format(LATITUDE, GEO)).FirstOrDefault();
XElement longitude = doc.Descendants(string.Format(LONGITUDE, GEO)).FirstOrDefault();
var lat = new Latitude(double.Parse(latitude.Value));
var lon = new Longitude(double.Parse(longitude.Value));
var a = new Atmosphere(t, h, p);
var l = new Location(lat, lon);
return new Conditions(a, l);
}
