DataSet.GetFloatValueAt Methods
Gets the float raster value from a cell at the specified position.
Overload List
| Name | Description | |
|---|---|---|
| Public method | GetFloatValueAt(Point point) | Gets the float raster value from a cell at the specified position, using bilinear interpolation if the dataset is continuous. |
| Public method | GetFloatValueAt(Point point, RasterFilter rasterFilter) | Gets the float raster value from a cell at the specified position, using a given interpolation method. |
GetFloatValueAt(Point point)
Gets the float raster value from a cell at the specified position, using bilinear interpolation if the dataset is continuous.Syntax
public System.Single GetFloatValueAt (
Point point
)Parameters
The position, expressed in the coordinate reference system of the dataset, to get a value at.
Return Value
The value at the specified position.
Remarks
This method locates a raster covering point, and retrieves the cell value at point from the raster. If several rasters cover the point, then the highest well-defined cell value at the point is returned. If no raster is found that covers the point, or if the cells surrounding point in all found rasters are undefined, an exception will be thrown.
This method is similar to the GetValueAt method, except that this method retrieves raster values as floating point values.
The lookup method will be either nearest-neighbor or bilinear interpolation, depending on whether the dataset is continuous. The bilinear interpolation will be used only for each individual raster, so it will be imperfect near data tile boundaries. See also the other variant of this method, and the basic RasterGeometry.GetFloatValue method, for more details about interpolation.
If the raster contains RGB or RGBA values, the returned value will be the average of the three color channels, i.e. the intensity of the color, using nearest-neighbor lookup.
Example
// Get the float value at Gothenburg
public static float GetFloatValueAtGothenburg(DataSet dataSet)
{
// The center coordinates of Gothenburg in Wgs8LongLat
Point gothenburgCenter = new Point(11.974560, 57.708870);
// Project the center coordinates of Gothenburg to the Crs of the DataSet
gothenburgCenter = dataSet.Crs.ProjectFromLongLat(gothenburgCenter);
// Get the float value at Gothenburg center and return it.
// If no raster is found that covers the point,
// or if the cells surrounding point in all found rasters are undefined,
// an exception will be thrown.
return dataSet.GetFloatValueAt(gothenburgCenter);
}
GetFloatValueAt(Point point, RasterFilter rasterFilter)
Gets the float raster value from a cell at the specified position, using a given interpolation method.Syntax
public System.Single GetFloatValueAt (
Point point,
RasterFilter rasterFilter
)Parameters
The position, expressed in the coordinate reference system of the dataset, to get a value at.
The interpolation method: either nearest-neighbor, bilinear or bicubic.
Return Value
The value at the specified position.
Remarks
This method locates a raster covering point, and retrieves the cell value at point from the raster. If several rasters cover the point, then the highest well-defined cell value at the point is returned. If no raster is found that covers the point, or if the cells surrounding point in all found rasters are undefined, an exception will be thrown.
This method is similar to the GetValueAt method, except that this method retrieves raster values as floating point values.
The lookup method will be either nearest-neighbor or bilinear or bicubic interpolation, depending on the given rasterFilter, but note that interpolation makes sense only if the dataset is continuous. The bilinear interpolation will be used only for each individual raster, so it will be imperfect near data tile boundaries, but with bicubic interpolation, rasters with the same resolution and Crs will be merged first. See also the other variant of this method, and the basic RasterGeometry.GetFloatValue method, for more details about interpolation.
If the raster contains RGB or RGBA values, the returned value will be the average of the three color channels, i.e. the intensity of the color, but note that only nearest-neighbor lookup is supported – an attempt to use bicubic or bilinear interpolation on RGB or RGBA values will throw an exception.
Platforms
Windows, Linux, Android