Class: QgsRasterCalculator

Performs raster layer calculations.

Methods

lastError

Returns a description of the last error encountered.

processCalculation

Starts the calculation and writes a new raster.

Attributes

BandError

CalculationError

Canceled

CreateOutputError

InputLayerError

MemoryError

ParserError

Success

class qgis.analysis.QgsRasterCalculator[source]

Bases: object

__init__(formulaString: str | None, outputFile: str | None, outputFormat: str | None, outputExtent: QgsRectangle, nOutputColumns: int, nOutputRows: int, rasterEntries: Iterable[QgsRasterCalculatorEntry], transformContext: QgsCoordinateTransformContext)

QgsRasterCalculator constructor.

Parameters:

  • formulaString (Optional[str]) – formula for raster calculation

  • outputFile (Optional[str]) – output file path

  • outputFormat (Optional[str]) – output file format

  • outputExtent (QgsRectangle) – output extent. CRS for output is taken from first entry in rasterEntries.

  • nOutputColumns (int) – number of columns in output raster

  • nOutputRows (int) – number of rows in output raster

  • rasterEntries (Iterable[QgsRasterCalculatorEntry]) – list of referenced raster layers

  • transformContext (QgsCoordinateTransformContext) – coordinate transformation context

Added in version 3.8.

__init__(formulaString: str | None, outputFile: str | None, outputFormat: str | None, outputExtent: QgsRectangle, outputCrs: QgsCoordinateReferenceSystem, nOutputColumns: int, nOutputRows: int, rasterEntries: Iterable[QgsRasterCalculatorEntry], transformContext: QgsCoordinateTransformContext)

QgsRasterCalculator constructor.

Parameters:

  • formulaString (Optional[str]) – formula for raster calculation

  • outputFile (Optional[str]) – output file path

  • outputFormat (Optional[str]) – output file format

  • outputExtent (QgsRectangle) – output extent, CRS is specified by outputCrs parameter

  • outputCrs (QgsCoordinateReferenceSystem) – destination CRS for output raster

  • nOutputColumns (int) – number of columns in output raster

  • nOutputRows (int) – number of rows in output raster

  • rasterEntries (Iterable[QgsRasterCalculatorEntry]) – list of referenced raster layers

  • transformContext (QgsCoordinateTransformContext) – coordinate transformation context

Added in version 3.8.

__init__(formulaString: str | None, outputFile: str | None, outputFormat: str | None, outputExtent: QgsRectangle, nOutputColumns: int, nOutputRows: int, rasterEntries: Iterable[QgsRasterCalculatorEntry])

QgsRasterCalculator constructor.

Parameters:

  • formulaString (Optional[str]) – formula for raster calculation

  • outputFile (Optional[str]) – output file path

  • outputFormat (Optional[str]) – output file format

  • outputExtent (QgsRectangle) – output extent. CRS for output is taken from first entry in rasterEntries.

  • nOutputColumns (int) – number of columns in output raster

  • nOutputRows (int) – number of rows in output raster

  • rasterEntries (Iterable[QgsRasterCalculatorEntry]) – list of referenced raster layers

Deprecated since version 3.8: Use the version with transformContext instead.

__init__(formulaString: str | None, outputFile: str | None, outputFormat: str | None, outputExtent: QgsRectangle, outputCrs: QgsCoordinateReferenceSystem, nOutputColumns: int, nOutputRows: int, rasterEntries: Iterable[QgsRasterCalculatorEntry])

QgsRasterCalculator constructor.

Parameters:

  • formulaString (Optional[str]) – formula for raster calculation

  • outputFile (Optional[str]) – output file path

  • outputFormat (Optional[str]) – output file format

  • outputExtent (QgsRectangle) – output extent, CRS is specified by outputCrs parameter

  • outputCrs (QgsCoordinateReferenceSystem) – destination CRS for output raster

  • nOutputColumns (int) – number of columns in output raster

  • nOutputRows (int) – number of rows in output raster

  • rasterEntries (Iterable[QgsRasterCalculatorEntry]) – list of referenced raster layers

Deprecated since version 3.8: Use the version with transformContext instead.

__init__(a0: QgsRasterCalculator)
Parameters:

a0 (QgsRasterCalculator)

BandError = 6
CalculationError = 7
Canceled = 3
CreateOutputError = 1
InputLayerError = 2
MemoryError = 5
ParserError = 4
class Result

Bases: int

Success = 0
lastError(self) → str[source]

Returns a description of the last error encountered.

Added in version 3.4.

Return type:

str

processCalculation(self, feedback: QgsFeedback | None = None) → QgsRasterCalculator.Result[source]

Starts the calculation and writes a new raster.

The optional feedback argument can be used for progress reporting and cancellation support.

Return type:

QgsRasterCalculator.Result

Returns:

QgsRasterCalculator.Success in case of success. If an error is encountered then a description of the error can be obtained by calling lastError().

Parameters:

feedback (Optional[QgsFeedback] = None)