Set Null
Set Null uses a specific cell value as the criteria (defined by users), if the conditional evaluation is True, the cell location will be assigned NoData; if it is False, the cell location will be assigned the value defined. If a cell value in the conditional raster is NoData, the output cell value is NoData as well. But NoData does not equate to False.
In the example below, we perform Set Null to a raster, set the expression to output NoData when the cell value is equal to 4(True); otherwise, output as value of False. The result will be shown as figures below.
Description of Parameters
Item |
Description |
Data Type |
Conditional Raster |
The raster data to be performed conditional analysis. |
Raster layer |
False Raster or Constant |
If evaluated as False, the output cell value will be assigned this value. If you choose to input a raster, it means the cell value of the identical position will be taken to be the output value. Users can click the |
Raster layer/ constant |
Expression |
Conditional expression. You can input the SQL expression. If you input [Value]>100 AND [Value]<180, it means the cell value between 100~180 will be identified as True(NoData); otherwise False. |
SQL expression |
Output Raster |
The filename and storage path of the output result. |
Raster layer |
icon to select different bands of the raster.
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