DataSet.TryGetValueAt Methods
Gets the integer value from a raster cell at the specified position.
Overload List
| Name | Description | |
|---|---|---|
 Public method | TryGetValueAt(Point point, out System.Int32 value) | Gets the integer value from a raster cell at the specified position, using bilinear interpolation if the dataset is continuous. |
| Public method | TryGetValueAt(Point point, RasterFilter rasterFilter, out System.Int32 value) | Gets the integer value from a raster cell at the specified position, using a given interpolation method. |
TryGetValueAt(Point point, out System.Int32 value)
Gets the integer value from a raster cell at the specified position, using bilinear interpolation if the dataset is continuous.Syntax
public System.Boolean TryGetValueAt (
Point point,
out System.Int32 value
)Parameters
The position, expressed in the coordinate reference system of the dataset, to get a value at.
Output parameter to return the raster value. If the method returns False, the value is undefined.
Return Value
In C# and C++ this method returns True if a raster value is found and False otherwise. In Java and Python, the actual value is returned, or null (Java) or None (Python) if no raster value is found.
Remarks
This method is similar to GetValueAt, except that it will return False, null (Java) or None (Python) on failure instead of throwing an exception.
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.GetCellValue method, for more details about interpolation.
Example
// Try to get the integer value at Gothenburg
public static bool TryGetValueAtGothenburg(DataSet dataSet, out int value)
{
// 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);
// Try to get the integer value at Gothenburg center and return it.
// This method is similar to GetValueAt, except that it will return
// false on failure instead of throwing an exception.
return dataSet.TryGetValueAt(gothenburgCenter, out value);
}
TryGetValueAt(Point point, RasterFilter rasterFilter, out System.Int32 value)
Gets the integer value from a raster cell at the specified position, using a given interpolation method.Syntax
public System.Boolean TryGetValueAt (
Point point,
RasterFilter rasterFilter,
out System.Int32 value
)Parameters
The position, in the coordinate reference system of the dataset, to get a value at.
The interpolation method: either nearest-neighbor, bilinear or bicubic.
Output parameter to return the raster value. If the method returns False, the value is undefined.
Return Value
In C# and C++ this method returns True if a raster value is found and False otherwise. In Java and Python, the actual value is returned, or null (Java) or None (Python) if no raster value is found.
Remarks
This method is similar to GetValueAt, except that it will return False, null (Java) or None (Python) on failure instead of throwing an exception.
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.GetCellValue method, for more details about interpolation.
Example
// Try to get the integer value at Gothenburg, using bicubic interpolation.
public static bool TryGetValueAtGothenburgBicubic(DataSet dataSet, out int value)
{
// 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);
// Try to get the integer value at Gothenburg center and return it.
// This method is similar to GetValueAt, except that it will return
// false on failure instead of throwing an exception.
return dataSet.TryGetValueAt(gothenburgCenter, RasterFilter.Bicubic, out value);
}
Platforms
Windows, Linux, Android