public void GhcnTempUncertaintyTest()
{
string etopoLocalUri = TestConstants.UriEtopo;
var ghcnStorage = TestDataStorageFactory.GetStorage(TestConstants.UriGHCN);
var etopoStorage = TestDataStorageFactory.GetStorage(etopoLocalUri);
GHCNDataHandler handler = new GHCNDataHandler(ghcnStorage);
ETOPO1DataSource.ETOPO1DataHandler elevationHandler = new ETOPO1DataSource.ETOPO1DataHandler(etopoStorage);
TimeRegion tr = new TimeRegion(firstYear: 1921, lastYear: 1921).GetMonthlyTimeseries(firstMonth: 3, lastMonth: 3); //data index 2642
FetchDomain domain = FetchDomain.CreatePoints(
new double[] { 36.27 }, //exact station. data index 3776
new double[] { -90.97 },
tr);
FetchRequest tempRequest = new FetchRequest("temp", domain);
Func <FetchRequest, Array> elevHandling = req =>
{
var rewrittenReq = new FetchRequest("Elevation", req.Domain);
return(elevationHandler.AggregateAsync(RequestContextStub.GetStub(etopoStorage, rewrittenReq), null).Result);
};
var reqContext = RequestContextStub.GetStub(ghcnStorage, tempRequest, elevHandling);
var compCont = new ComputationalContext();
Assert.AreEqual(0.0, (double)handler.EvaluateAsync(reqContext, compCont).Result.GetValue(0), 1e-6); //manual data comparison.
}
public void GHCNplaneInterpolationCellTest()
{
//with lapse rate correction
FetchDomain fd = FetchDomain.CreateCells(new double[] { 1.5 }, new double[] { 1.0 }, new double[] { 1.6 }, new double[] { 1.1 }, new TimeRegion(firstYear: 1970, lastYear: 1970, firstDay: 91, lastDay: 120)); //april
FetchRequest fr = new FetchRequest("temp", fd);
GhcnPlaneStorageContext storage = new GhcnPlaneStorageContext(fr);
GHCNDataHandler sotdh = new GHCNDataHandler(storage);
var compCont = new ComputationalContext();
var evRes = sotdh.EvaluateAsync(storage, compCont).Result;
var result = (double[])sotdh.AggregateAsync(storage, compCont).Result;
Assert.AreEqual(-7.0, result[0], TestConstants.DoublePrecision);
//without lapse rate correction
fd = FetchDomain.CreateCells(new double[] { -2.5 }, new double[] { 1.0 }, new double[] { -2.4 }, new double[] { 1.1 }, new TimeRegion(firstYear: 1970, lastYear: 1970, firstDay: 91, lastDay: 120)); //april
fr = new FetchRequest("temp", fd);
storage = new GhcnPlaneStorageContext(fr);
sotdh = new GHCNDataHandler(storage);
compCont = new ComputationalContext();
evRes = sotdh.EvaluateAsync(storage, compCont).Result;
result = (double[])sotdh.AggregateAsync(storage, compCont).Result;
Assert.AreEqual(-6.0, result[0], TestConstants.DoublePrecision);
}
public void GHCNtempInterpolationPointsTest()
{
FetchDomain fd = FetchDomain.CreatePoints(new double[] { 1.5 }, new double[] { 1.0 }, new TimeRegion(firstYear: 1970, lastYear: 1970, firstDay: 60, lastDay: 90)); //mar
FetchRequest fr = new FetchRequest("temp", fd);
GhcnStorageContext storage = new GhcnStorageContext(fr);
GHCNDataHandler sotdh = new GHCNDataHandler(storage);
var compCont = new ComputationalContext();
var evRes = sotdh.EvaluateAsync(storage, compCont).Result;
var result = (double[])sotdh.AggregateAsync(storage, compCont).Result; //val = 3/5*lat-1 = 3/5*(1.5)-1 = -0.1
Assert.AreEqual(-0.1, result[0], TestConstants.DoublePrecision);
fd = FetchDomain.CreatePoints(new double[] { -2.5 }, new double[] { 1.0 }, new TimeRegion(firstYear: 1970, lastYear: 1970, firstDay: 60, lastDay: 90)); //mar
fr = new FetchRequest("temp", fd);
storage = new GhcnStorageContext(fr);
sotdh = new GHCNDataHandler(storage);
compCont = new ComputationalContext();
evRes = sotdh.EvaluateAsync(storage, compCont).Result;
result = (double[])sotdh.AggregateAsync(storage, compCont).Result; //val = 3/5*lat = 3/5*(-2.5) = -1.5
Assert.AreEqual(-1.5, result[0], TestConstants.DoublePrecision);
}
public void GHCNprateInterpolationPointsTest()
{
FetchDomain fd = FetchDomain.CreatePoints(new double[] { 0.5 }, new double[] { 1.0 }, new TimeRegion(firstYear: 1970, lastYear: 1970, firstDay: 91, lastDay: 120)); //april
FetchRequest fr = new FetchRequest("prate", fd);
GhcnStorageContext storage = new GhcnStorageContext(fr);
GHCNDataHandler sotdh = new GHCNDataHandler(storage);
var compCont = new ComputationalContext();
var evRes = sotdh.EvaluateAsync(storage, compCont).Result;
var result = (double[])sotdh.AggregateAsync(storage, compCont).Result; //val = 6/5*lat = 6/5*(0.5) = -3
Assert.AreEqual(0.6, result[0], TestConstants.DoublePrecision);
fd = FetchDomain.CreatePoints(new double[] { -5.0 }, new double[] { 1.0 }, new TimeRegion(firstYear: 1970, lastYear: 1970, firstDay: 91, lastDay: 120)); //april
fr = new FetchRequest("prate", fd);
storage = new GhcnStorageContext(fr);
sotdh = new GHCNDataHandler(storage);
compCont = new ComputationalContext();
evRes = sotdh.EvaluateAsync(storage, compCont).Result;
result = (double[])sotdh.AggregateAsync(storage, compCont).Result; //val = 6/5*lat = 6/5*(-2.5) = -3
Assert.AreEqual(0.0, result[0], TestConstants.DoublePrecision); //as prate can't be negative, it is coerced to zero
}
public void GHCNnanForOutOfObsConvexHullTest()
{
FetchDomain fd = FetchDomain.CreatePoints(new double[] { -10 }, new double[] { 1.0 }, new TimeRegion(firstYear: 1970, lastYear: 1970, firstDay: 60, lastDay: 90)); //mar
FetchRequest fr = new FetchRequest("prate", fd);
GhcnStorageContext storage = new GhcnStorageContext(fr);
GHCNDataHandler sotdh = new GHCNDataHandler(storage);
var compCont = new ComputationalContext();
var evRes = (double[])sotdh.EvaluateAsync(storage, compCont).Result;
Assert.IsTrue(double.IsNaN(evRes[0]));
var result = (double[])sotdh.AggregateAsync(storage, compCont).Result; //must be NAN as requested point out of observations convex hull
Assert.IsTrue(double.IsNaN(result[0]));
}
public void Bug1691()
{
double BayOfBiscaySELat = 44.5;
double BayOfBiscaySELon = -3.5;
double InFranceLat = 47;
double InFranceLon = 1;
Random r = new Random(1);
var eps = r.NextDouble() / 10.0;
double latDelta = InFranceLat - BayOfBiscaySELat;
double lonDelta = InFranceLon - BayOfBiscaySELon;
var tr = new TimeRegion(1990, 2001, 1, -1, 0, 24, true, false, true);
var request = new FetchRequest(
"temp",
FetchDomain.CreateCellGrid(
Enumerable.Range(0, 31).Select(i => eps + BayOfBiscaySELat + i * latDelta / 31.0).ToArray(),
Enumerable.Range(0, 21).Select(i => eps + BayOfBiscaySELon + i * lonDelta / 21.0).ToArray(),
tr));
string etopoLocalUri = TestConstants.UriEtopo;
var ghcnStorage = TestDataStorageFactory.GetStorage(TestConstants.UriGHCN);
var etopoStorage = TestDataStorageFactory.GetStorage(etopoLocalUri);
GHCNDataHandler handler = new GHCNDataHandler(ghcnStorage);
ETOPO1DataSource.ETOPO1DataHandler elevationHandler = new ETOPO1DataSource.ETOPO1DataHandler(etopoStorage);
Func <FetchRequest, Array> elevHandling = req =>
{
var rewrittenReq = new FetchRequest("Elevation", req.Domain);
return(elevationHandler.AggregateAsync(RequestContextStub.GetStub(etopoStorage, rewrittenReq), null).Result);
};
var reqContext = RequestContextStub.GetStub(ghcnStorage, request, elevHandling);
var compCont = new ComputationalContext();
var evRes = handler.EvaluateAsync(reqContext, compCont).Result;
Assert.IsTrue(-70.0 < (double)handler.AggregateAsync(reqContext, compCont).Result.GetValue(16, 2, 0)); //manual data comparison.
}
public void GhcnPrateUncertaintyTest()
{
System.Diagnostics.Trace.WriteLine(TestConstants.UriGHCN);
var storage = TestDataStorageFactory.GetStorage(TestConstants.UriGHCN);
GHCNDataHandler handler = new GHCNDataHandler(storage);
TimeRegion tr = new TimeRegion(firstYear: 1914, lastYear: 1914).GetMonthlyTimeseries(firstMonth: 12, lastMonth: 12); //data index 2567
FetchDomain domain = FetchDomain.CreatePoints(
new double[] { -25.18 }, //exact station. data index 18398
new double[] { 151.65 },
tr);
FetchRequest prateRequest = new FetchRequest("prate", domain);
var compCont = new ComputationalContext();
var reqContext = RequestContextStub.GetStub(storage, prateRequest);
Assert.AreEqual(0.0, (double)handler.EvaluateAsync(reqContext, compCont).Result.GetValue(0), 1e-6); //manual data comparison.
}
public void PlaneInterpolationTest()
{
double[] lats = new double[] { 0.0, 5.0, 5.0 };
double[] lons = new double[] { 0.0, 0.0, 6.0 };
double[] vals = new double[] { 0.0, 3.0, 3.0 };
FetchDomain fd = FetchDomain.CreatePoints(new double[] { -5.0 }, new double[] { 6.0 }, new TimeRegion());
FetchRequest fr = new FetchRequest("val", fd);
var storage = new SimplePlaneStorageContext(lats, lons, vals, fr);
storage.Request = fr;
SpatialOnlyTpsDataHandler sotdh = new SpatialOnlyTpsDataHandler(storage);
var compContext = new ComputationalContext();
sotdh.EvaluateAsync(storage, compContext);
var result = (double[])sotdh.AggregateAsync(storage, compContext).Result;
Assert.AreEqual(-3.0, result[0], TestConstants.DoublePrecision);
}
public void SparsePointsYieldNansOrPlane()
{
double[] lats = new double[] { 0.0, 5.0, 50.0 };
double[] lons = new double[] { 0.0, 0.0, 0.0 };
double[] vals = new double[] { 1.0, 1.0, 1.0 };
FetchDomain fd = FetchDomain.CreatePoints(new double[] { 7.0 }, new double[] { 6.0 }, new TimeRegion());
FetchRequest fr = new FetchRequest("val", fd);
var storage = new SimplePlaneStorageContext(lats, lons, vals, fr);
storage.Request = fr;
SpatialOnlyTpsDataHandler sotdh = new SpatialOnlyTpsDataHandler(storage);
ComputationalContext cc = new ComputationalContext();
var unc = sotdh.EvaluateAsync(storage, cc).Result;
var result = (double[])sotdh.AggregateAsync(storage, cc).Result;
Assert.IsTrue(double.IsNaN(result[0]) || Math.Abs(1.0 - result[0]) < TestConstants.FloatPrecision);
}
protected virtual async Task <double> CalculateCellMean(IRequestContext requestContext, ComputationalContext computationalContext, double latmin, double latmax, double lonmin, double lonmax, double[] obsLats, double[] obsLons, double[] obsVals)
{
if (latmin == latmax && lonmin == lonmax)
{
return(spatialIntegrator.Interpolate(latmin, lonmin, obsLats, obsLons, obsVals));
}
//non-zero area
var interpolationContext = spatialIntegrator.GetInterpolationContext(obsLats, obsLons, obsVals);
double latStep = (latmax - latmin) / 19.0;
double lonStep = (lonmax - lonmin) / 19.0;
double acc = 0.0;
double r;
for (int i = 0; i < 20; i++)
{
for (int j = 0; j < 20; j++)
{
r = spatialIntegrator.Interpolate(latmin + latStep * i, lonmin + lonStep * j, interpolationContext);
acc += r;
}
}
return(acc / 400.0);
}
/// <summary>
/// Returns a set of linear weights along with timeSegmint for with dataIndeces in linear weights are valid
/// </summary>
/// <param name="context"></param>
/// <param name="computationalContext"></param>
/// <param name="cells"></param>
/// <returns></returns>
protected IEnumerable <Tuple <ITimeSegment, LinearWeight[]> > CalcLinearWeights(ComputationalContext computationalContext, IEnumerable <GeoCellTuple> cells)
{
if (!computationalContext.ContainsKey("observations"))
{
throw new InvalidOperationException("Call SaveObservationsAndDalanayDiagsForCells prior calling CompleteAggregateCellsBatch");
}
ISpatPointsLinearInterpolator2D spli2d = (ISpatPointsLinearInterpolator2D)spatialIntegrator;
Dictionary <ITimeSegment, IObservationsInformation> observations = (Dictionary <ITimeSegment, IObservationsInformation>)computationalContext["observations"];
Dictionary <ITimeSegment, object> delanays = (Dictionary <ITimeSegment, object>)computationalContext["dalanays"];
var sw1 = System.Diagnostics.Stopwatch.StartNew();
TraceVerbose("Computing field values");
//WARNING: can't be paralleled as dalanays are not thread safe
foreach (var cell in cells)
{
var timeSegment = cell.Time;
var observation = observations[timeSegment].Observations;
object delanay = delanays[timeSegment];
double latmax = cell.LatMax, latmin = cell.LatMin, lonmax = cell.LonMax, lonmin = cell.LonMin;
if (latmax == latmin && lonmax == lonmin)
{
yield return(Tuple.Create(timeSegment, spli2d.GetLinearWeigths(latmin, lonmin, delanay)));
}
else
{
var sizeSqrt = (int)Math.Sqrt(cellAveragingGridSize);
LinearWeight[][] toFlatten = new LinearWeight[sizeSqrt * sizeSqrt][];
double latStep = (latmax - latmin) / (sizeSqrt - 1);
double lonStep = (lonmax - lonmin) / (sizeSqrt - 1);
for (int i = 0; i < sizeSqrt; i++)
{
for (int j = 0; j < sizeSqrt; j++)
{
var w = spli2d.GetLinearWeigths(latmin + latStep * i, lonmin + lonStep * j, delanay);
toFlatten[sizeSqrt * i + j] = w;
}
}
var devisor = sizeSqrt * sizeSqrt;
var flattenedWeights = toFlatten.SelectMany(weights => weights).GroupBy(w => w.DataIndex).Select(g => new LinearWeight(g.Key, g.Select(g1 => g1.Weight).Sum() / devisor)).ToArray();
yield return(Tuple.Create(timeSegment, flattenedWeights));
}
}
TraceVerbose("Computing field values finished in {0}", sw1.Elapsed);
}
/// <summary>
/// Computes delanay triangulation for each unique time segment that is present in the cells enumeration. Saves them into comp context
/// </summary>
/// <param name="context"></param>
/// <param name="computationalContext"></param>
/// <param name="cells"></param>
/// <returns></returns>
protected async Task SaveObservationsAndDalanayDiagsForCells(IRequestContext context, ComputationalContext computationalContext, IEnumerable <GeoCellTuple> cells)
{
var variable = context.Request.EnvironmentVariableName;
var cellsArray = cells.ToArray();
var numberedCells = Enumerable.Zip(cellsArray, Enumerable.Range(0, int.MaxValue), (cell, num) => Tuple.Create(cell, num)).ToArray();
var missingValue = MissingValuesDictionary[variable];
int count = numberedCells.Length;
Dictionary <ITimeSegment, IObservationsInformation> observations = new Dictionary <ITimeSegment, IObservationsInformation>();
Dictionary <ITimeSegment, object> delanays = new Dictionary <ITimeSegment, object>();
var timeGroups = numberedCells.GroupBy(cell => cell.Item1.Time).ToArray();
//fetching observations for different timeSegments, constructing delanay triangulations for them. storing them into the comp context
TraceVerbose("Fetching observations for different time segments, building delanays in parallel");
var timeSegmentGroupedTasks = timeGroups.Select(group =>
Task.Run(async() =>
{
var timeSegment = group.Key;
int groupHashCode = group.GetHashCode();
TraceVerbose("Getting observations for time segment {0}", groupHashCode);
System.Diagnostics.Stopwatch sw1 = System.Diagnostics.Stopwatch.StartNew();
var observation = await observationProvider.GetObservationsAsync(context, variable, missingValue, 0.0, 0.0, 0.0, 0.0, timeSegment);
sw1.Stop();
TraceVerbose("Got observations for time segment {0} in {1}", groupHashCode, sw1.Elapsed);
double[] lats = observation.Observations.Select(o => o.Latitude).ToArray();
double[] lons = observation.Observations.Select(o => o.Longitude).ToArray();
double[] vals = observation.Observations.Select(o => o.Value).ToArray();
TraceVerbose("Generating dalanay for time segment {0} ({1} observations)", groupHashCode, observation.Observations.Length);
System.Diagnostics.Stopwatch sw2 = System.Diagnostics.Stopwatch.StartNew();
var dalanay = nni.GetInterpolationContext(lats, lons, vals);
sw2.Stop();
TraceVerbose("Generated dalanay for time segment {0} ({1} observations) in {2}", groupHashCode, observation.Observations.Length, sw2.Elapsed);
observations.Add(timeSegment, observation);
delanays.Add(timeSegment, dalanay);
}));
var syncTask = Task.WhenAll(timeSegmentGroupedTasks);
await syncTask;
TraceVerbose("Fetched observations for different time segments. Delanay triangulations are computed");
computationalContext["observations"] = observations;
computationalContext["dalanays"] = delanays;
computationalContext["requestCells"] = cellsArray;
}
protected async override Task <double[]> AggregateCellsBatchAsync(IRequestContext context, ComputationalContext computationalContext, IEnumerable <GeoCellTuple> cells)
{
await SaveObservationsAndDalanayDiagsForCells(context, computationalContext, cells);
Dictionary <ITimeSegment, IObservationsInformation> observations = (Dictionary <ITimeSegment, IObservationsInformation>)computationalContext["observations"];
var res = CalcLinearWeights(computationalContext, cells).Select(t =>
{
var releventObservations = observations[t.Item1].Observations;
return(t.Item2.Sum(x => x.Weight * releventObservations[x.DataIndex].Value));
}).ToArray();
return(res);
}
protected override async Task <double[]> EvaluateCellsBatchAsync(IRequestContext context, ComputationalContext computationalContext, IEnumerable <GeoCellTuple> cells)
{
await SaveObservationsAndDalanayDiagsForCells(context, computationalContext, cells);
VariogramModule.IVariogramFitter variogramFitter = new LMDotNetVariogramFitter.Fitter();
Dictionary <ITimeSegment, VariogramModule.IVariogram> variograms = new Dictionary <ITimeSegment, VariogramModule.IVariogram>();
Dictionary <ITimeSegment, IObservationsInformation> observations = (Dictionary <ITimeSegment, IObservationsInformation>)computationalContext["observations"];
LimitedConcurrencyLevelTaskScheduler lclts = new LimitedConcurrencyLevelTaskScheduler(Environment.ProcessorCount);
TaskFactory taskFactory = new TaskFactory(lclts);
var variogramTasks = observations.Select(pair => taskFactory.StartNew(() =>
{
ITimeSegment ts = pair.Key;
TraceVerbose(string.Format("Fitting variogram for {0} ({1} observations)", ts, pair.Value.Observations.Length));
Stopwatch sw1 = Stopwatch.StartNew();
var lats = pair.Value.Observations.Select(o => o.Latitude).ToArray();
var lons = pair.Value.Observations.Select(o => o.Longitude).ToArray();
var vals = pair.Value.Observations.Select(o => o.Value).ToArray();
var pointSet = new EmpVariogramBuilder.PointSet(lats, lons, vals);
var dist = FuncConvert.ToFSharpFunc(new Converter <Tuple <double, double>, FSharpFunc <Tuple <double, double>, double> >(t1 =>
FuncConvert.ToFSharpFunc(new Converter <Tuple <double, double>, double>(t2 => SphereMath.GetDistance(t1.Item1, t1.Item2, t2.Item1, t2.Item2)))));
var empVar = EmpVariogramBuilder.EmpiricalVariogramBuilder.BuildEmpiricalVariogram(pointSet, dist);
var fitted_variogram = variogramFitter.Fit(empVar);
VariogramModule.IVariogram effectiveVariogram = null;
sw1.Stop();
if (FSharpOption <VariogramModule.IDescribedVariogram> .get_IsSome(fitted_variogram))
{
effectiveVariogram = fitted_variogram.Value;
TraceVerbose(string.Format("Variogram fited for {0} ({1} observations) in {2}", ts, pair.Value.Observations.Length, sw1.Elapsed));
}
else
{
TraceWarning(string.Format("Variogram fitting failed for {0} ({1} observations) in {2}. Using fallback variogram", ts, pair.Value.Observations.Length, sw1.Elapsed));
effectiveVariogram = variogramFitter.GetFallback(empVar);
}
lock ("saving_variograms")
{
variograms.Add(ts, effectiveVariogram);
}
}));
TraceVerbose(string.Format("Starting calculations of linear weights for all cells"));
Stopwatch sw2 = Stopwatch.StartNew();
var weigths = CalcLinearWeights(computationalContext, cells);
sw2.Stop();
TraceVerbose(string.Format("calculations of linear weights for all cells ended in {0}", sw2.Elapsed));
TraceVerbose(string.Format("Waiting for all variograms to be computed"));
await Task.WhenAll(variogramTasks);
TraceVerbose(string.Format("All variograms are computed. Calculating variances and values"));
Stopwatch sw3 = Stopwatch.StartNew();
var resultValues = cells.Zip(weigths, (cell, weightTuple) =>
{
ITimeSegment ts = cell.Time;
var weight = weightTuple.Item2;
VariogramModule.IVariogram variogram = variograms[ts];
var observation = observations[ts].Observations;
Debug.Assert(Math.Abs(weight.Sum(w => w.Weight) - 1.0) < 1e-10);
double sill = variogram.Sill;
double cellLat = (cell.LatMax + cell.LatMin) * 0.5;
double cellLon = (cell.LonMax + cell.LonMin) * 0.5;
//var = cov(0)+ sum sum (w[i]*w[j]*cov(i,j))-2.0*sum(w[i]*cov(x,i))
double cov_at_0 = sill;
double acc = cov_at_0; //cov(0)
for (int i = 0; i < weight.Length; i++)
{
double w = weight[i].Weight;
int idx1 = weight[i].DataIndex;
double lat1 = observation[idx1].Latitude;
double lon1 = observation[idx1].Longitude;
for (int j = 0; j < i; j++)
{
int idx2 = weight[j].DataIndex;
double lat2 = observation[idx2].Latitude;
double lon2 = observation[idx2].Longitude;
double dist = SphereMath.GetDistance(lat1, lon1, lat2, lon2);
double cov = sill - variogram.GetGamma(dist);
acc += 2.0 * w * weight[j].Weight * cov;
}
acc += w * w * cov_at_0; //diagonal elements
double dist2 = SphereMath.GetDistance(lat1, lon1, cellLat, cellLon);
double cov2 = sill - variogram.GetGamma(dist2);
acc -= 2.0 * w * cov2;
}
return(Tuple.Create(cell, Math.Sqrt(acc), weight.Sum(w => observation[w.DataIndex].Value * w.Weight)));
}).ToArray();
sw3.Stop();
TraceVerbose(string.Format("All sigmas calulated in {0}", sw3.Elapsed));
computationalContext.Add("results", resultValues);
return(resultValues.Select(r => r.Item2).ToArray());
}
protected async override Task <double[]> AggregateCellsBatchAsync(IRequestContext context, ComputationalContext computationalContext, IEnumerable <GeoCellTuple> cells)
{
TraceVerbose(string.Format("Aggregation: exracting already computed values"));
Stopwatch sw = Stopwatch.StartNew();
Tuple <GeoCellTuple, double, double>[] precomputed = (Tuple <GeoCellTuple, double, double>[])computationalContext["results"];
int idx = 0;
GeoCellTuple[] cellsArray = cells.ToArray();
int n = cellsArray.Length;
double[] res = new double[n];
for (int aggIdx = 0; aggIdx < n; aggIdx++)
{
while (!cellsArray[aggIdx].Equals(precomputed[idx].Item1))
{
idx++;
}
res[aggIdx] = precomputed[idx].Item3;
}
sw.Stop();
TraceVerbose(string.Format("Aggregation: extracted values in {0}", sw.Elapsed));
return(res);
}