Class: QgsRasterCalculator¶

Performs raster layer calculations.

Enums

Result

Result of the calculation

Methods

`creationOptions`	Returns the list of data source creation options which will be used when creating the output raster file.
`lastError`	Returns a description of the last error encountered.
`noDataValue`	Returns no data value used for output file.
`processCalculation`	Starts the calculation and writes a new raster.
`setCreationOptions`	Sets a list of data source creation options to use when creating the output raster file.
`setNoDataValue`	Set no data value for output file.

class qgis.analysis.QgsRasterCalculator[source]¶

Bases: object

__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], 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])

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__(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__(a0: QgsRasterCalculator)

Parameters:: a0 (QgsRasterCalculator)

class Result(*values)¶

Bases: IntEnum

Result of the calculation

Success: Calculation successful
CreateOutputError: Error creating output data file
InputLayerError: Error reading input layer
Canceled: User canceled calculation
ParserError: Error parsing formula
MemoryError: Error allocating memory for result
BandError: Invalid band number for input
CalculationError: Error occurred while performing calculation

creationOptions(self) → List[str][source]¶

Returns the list of data source creation options which will be used when creating the output raster file.

See also

setCreationOptions()

Added in version 3.44.

Return type:: List[str]

lastError(self) → str[source]¶

Returns a description of the last error encountered.

Added in version 3.4.

Return type:: str

noDataValue(self) → float[source]¶

Returns no data value used for output file.

See also

setNoDataValue()

Added in version 3.44.

Return type:: float

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.Result.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)

setCreationOptions(self, options: Iterable[str | None])[source]¶

Sets a list of data source creation options to use when creating the output raster file.

See also

creationOptions()

Added in version 3.44.

Parameters:: options (Iterable[Optional[str]])

setNoDataValue(self, noDataValue: float)[source]¶

Set no data value for output file.

See also

noDataValue()

Added in version 3.44.

Parameters:: noDataValue (float)