private static ColumnScale <string> SpatialIndexAdvanced(string dataSetPath)
{
ColumnScale <string> columnScale = new ColumnScale <string>();
Driver fileGdbDriver = Ogr.GetDriverByName("OpenFileGDB");
DataSource dataSource = fileGdbDriver.Open(dataSetPath, 0);
Layer layer = dataSource.GetLayerByIndex(0);
Feature feature = layer.GetNextFeature();
while (feature != null)
{
string classification = feature.GetFieldAsString("CODE2012");
Geometry geometry = feature.GetGeometryRef();
double size = geometry.Area();
columnScale.AddFeature(classification, new FeatureScale()
{
FeatureId = (int)feature.GetFID(), Size = size
});
feature = layer.GetNextFeature();
}
columnScale.CalculateProbabilities();
foreach ((string classification, ColumnValueScale columnValueScale) in columnScale.ColumnValueScales)
{
Console.WriteLine(
$"Classification {classification} has an aggregated scale limit of {columnValueScale.ProbabilityLimit,8:P}.");
}
return(columnScale);
}
private static void SelectRandomFeatureWeighted(string dataSetPath, int sampleSize)
{
ColumnScale <string> columnScale = Program.SpatialIndexAdvanced(dataSetPath);
List <dynamic> result = new List <dynamic>();
Driver fileGdbDriver = Ogr.GetDriverByName("OpenFileGDB");
DataSource dataSource = fileGdbDriver.Open(dataSetPath, 0);
Layer layer = dataSource.GetLayerByIndex(0);
SpatialReference spatialReference = layer.GetSpatialRef();
List <int> featureIds = new List <int>();
Random random = new Random();
for (int i = 0; i < sampleSize; i++)
{
double randomValue = random.NextDouble();
KeyValuePair <string, ColumnValueScale> columnValueScale = columnScale.ColumnValueScales
.Where(x => x.Value.ProbabilityLimit > randomValue)
.Where(x => x.Value.Features.Any(y => !featureIds.Contains(y.FeatureId)))
.OrderBy(x => x.Value.ProbabilityLimit)
.FirstOrDefault();
if (columnValueScale.Value != null)
{
FeatureScale featureScale;
do
{
randomValue = random.NextDouble();
featureScale = columnValueScale.Value.Features.Where(x => x.ProbabilityLimit > randomValue)
.Where(x => !featureIds.Contains(x.FeatureId))
.OrderBy(x => x.ProbabilityLimit)
.FirstOrDefault();
}while (featureScale != null && featureIds.Contains(featureScale.FeatureId));
Feature feature = layer.GetFeature(featureScale.FeatureId);
featureIds.Add(featureScale.FeatureId);
result.Add(new
{
FeatureId = feature.GetFID(),
Classification = feature.GetFieldAsString("CODE2012"),
FeatureGeometry = Tools.GetSampleItemGeometriesPolygon(feature, spatialReference),
});
}
}
Console.WriteLine(JsonSerializer.Serialize(result, new JsonSerializerOptions {
WriteIndented = true
}));
}
