internal static IEnumerable<PgmCellCoords> findCellAndSurroundingNodesCoords(PgmCellCoords pgmCellCoords, double latIncrement, double lonIncrement)
{
IEnumerable<double> horizontalNodes = Enumerable.Range(-1, 4)
.Select(step => pgmCellCoords.Lon + step * lonIncrement);
IEnumerable<double> verticalNodes = Enumerable.Range(-1, 4)
.Select(step => pgmCellCoords.Lat + step * latIncrement);
return verticalNodes.SelectMany(lat => horizontalNodes.Select(lon => normalizeCoords(lat, lon)))
.ToList();
}
internal void ExtractingValuesFromSimpleSegmentsWorksCorrectly(
PgmCellCoords coords,
double latIncrement,
double lonIncrement,
IEnumerable<PgmCellCoords> expected)
{
var actual = PgmElevationProvider.findCellAndSurroundingNodesCoords(coords, latIncrement, lonIncrement);
AssertDeep.Equal(actual, expected);
}
private BivariatePolynomial getInterpolationForCellSurface(PgmCellCoords pgmCellCoords)
{
var nodesCoordinates = findCellAndSurroundingNodesCoords(pgmCellCoords,
dataDescription.LatitudeIncrementDegrees,
dataDescription.LongitudeIncrementDegrees);
var nodesUndulations = nodesCoordinates.Select(coor => _discreteSurface.GetUndulation(coor.Lat, coor.Lon));
var formattedUndulations = nodesUndulations.Select((c, i) => new {Index = i, value = c})
.GroupBy(p => p.Index / 4)
.Select(c => c.Select(v => v.value)
.ToList())
.ToList();
return BicubicCalculator.GetSpline(values: formattedUndulations, step: dataDescription.LatitudeIncrementDegrees);
}
internal void NormalizationWorksCorrectlyForNormalizedData(PgmCellCoords inputCoords, PgmCellCoords expectedCoords)
{
var actual = PgmElevationProvider.normalizeCoords(inputCoords.Lat, inputCoords.Lon);
AssertDeep.Equal(actual, expectedCoords, config => config.DoublePrecision = 1e-5);
}
