async Task <float> CalculatePollution(List <Position> pollutionPoints, bool main = false)
{
float overall = 0, max = 0;
if (pollutionPoints.Count > 0)
{
List <List <string> > list = new List <List <string> >();
for (int i = 0; i < pollutionPoints.Count; i++)
{
List <string> point = new List <string>();
point.Add(pollutionPoints[i].Latitude.ToString("F6"));
point.Add(pollutionPoints[i].Longitude.ToString("F6"));
list.Add(point);
}
PollutionRequest request = new PollutionRequest()
{
RAD = 50,
PAIRS = list
};
var result = await rest.GetPollution(JsonConvert.SerializeObject(request));
if (result != null)
{
int maxIndex = 0;
if (result.val.Count >= 5)
{
for (int index = 2; index < result.val.Count - 2; index++)
{
float subTotal = 0;
for (int j = index - 2; j < index + 2; j++)
{
subTotal += (float)Convert.ToDouble(result.val[j]);
}
if (subTotal > max)
{
max = subTotal;
maxIndex = index;
peak = max;
}
overall += (float)Convert.ToDouble(result.val[index]);
}
overall /= result.val.Count;
double lat, lng;
lat = Convert.ToDouble(result.lat[maxIndex]);
lng = Convert.ToDouble(result.lon[maxIndex]);
hotspot = new Position(lat, lng);
}
}
}
return(overall);
}
async Task <bool> GetHeatMap(Bounds bounds)
{
// set the size of the pixel in degrees lat / lon
map.Polygons.Clear();
map.Polylines.Clear();
// build the request for polution info
var request = new PollutionRequest();
request.RAD = 100;
request.PAIRS = new List <List <string> >();
var radius = Math.Max(bounds.HeightDegrees / 2, bounds.WidthDegrees / 2);
var unit = Math.Max(.0015, radius / 100);
var halfU = unit / 2;
var left = Convert.ToDouble((bounds.Center.Longitude + radius * 2).ToString("F6"));
var right = Convert.ToDouble((bounds.Center.Longitude - radius * 2).ToString("F6"));
var top = Convert.ToDouble((bounds.Center.Latitude + radius).ToString("F6"));
var bottom = Convert.ToDouble((bounds.Center.Latitude - radius).ToString("F6"));
for (var Y = bottom; Y <= top; Y += unit)
{
for (var X = left; X >= right; X -= unit)
{
List <string> point = new List <string>();
point.Add(Y.ToString());
point.Add(X.ToString());
(request.PAIRS).Add(point);
if (request.PAIRS.Count >= 400 || (Y + unit > top && X - unit < right))
{
var result = await rest.GetPollution(JsonConvert.SerializeObject(request));
if (result != null)
{
// get the results
var x = 0;
double lvl = 0;
// loop through the results
for (x = 0; x < result.lon.Count; x++)
{
string level = (result.val)[x];
lvl = Convert.ToDouble(level) * 1;
Color fc = Color.Black;
if (lvl <= 50)
{
fc = Color.Green;
}
else
{
if (lvl <= 100)
{
fc = Color.Yellow;
}
else
{
fc = Color.Red;
}
}
var north = Convert.ToDouble(result.lat[x]) * 1 + halfU * 1;
var south = Convert.ToDouble(result.lat[x]) * 1 - halfU * 1;
var east = Convert.ToDouble(result.lon[x]) * 1 + halfU * 1;
var west = Convert.ToDouble(result.lon[x]) * 1 - halfU * 1;
var tileBounds = new Bounds(new Position(south, west), new Position(north, east));
var rectangle = new Xamarin.Forms.GoogleMaps.Polygon();
rectangle.StrokeWidth = 0;
rectangle.FillColor = Color.FromRgba(255, 0, 0, (lvl / 30.0) - 0.25);
rectangle.Positions.Add(tileBounds.NorthEast);
rectangle.Positions.Add(tileBounds.NorthWest);
rectangle.Positions.Add(tileBounds.SouthWest);
rectangle.Positions.Add(tileBounds.SouthEast);
map.Polygons.Add(rectangle);
}
}
request.PAIRS.Clear();
}
}
}
return(true);
}