Class: QgsKernelDensityEstimation¶

Performs Kernel Density Estimation (“heatmap”) calculations on a vector layer.

Methods

`addFeature`	Adds a single feature to the KDE surface.
`finalise`	Finalises the output file.
`prepare`	Prepares the output file for writing and setups up the surface calculation.
`run`	Runs the KDE calculation across the whole layer at once.

Attributes

`DriverError`
`FileCreationError`
`InvalidParameters`
`KernelEpanechnikov`
`KernelQuartic`
`KernelTriangular`
`KernelTriweight`
`KernelUniform`
`OutputRaw`
`OutputScaled`
`RasterIoError`
`Success`

class qgis.analysis.QgsKernelDensityEstimation[source]¶

Bases: object

__init__(parameters: QgsKernelDensityEstimation.Parameters, outputFile: str | None, outputFormat: str | None)

Constructor for QgsKernelDensityEstimation. Requires a Parameters object specifying the options to use to generate the surface. The output path and file format are also required.

Parameters:

parameters (QgsKernelDensityEstimation.Parameters)
outputFile (Optional[str])
outputFormat (Optional[str])

DriverError = 1¶

FileCreationError = 3¶

InvalidParameters = 2¶

KernelEpanechnikov = 4¶

KernelQuartic = 0¶

class KernelShape¶: Bases: int

KernelTriangular = 1¶

KernelTriweight = 3¶

KernelUniform = 2¶

OutputRaw = 0¶

OutputScaled = 1¶

class OutputValues¶: Bases: int

class Parameters¶

Bases: object

KDE parameters

decayRatio¶: Decay ratio (Triangular kernels only)

outputValues¶: Type of output value

pixelSize¶: Size of pixel in output file

radius¶: Fixed radius, in map units

radiusField¶: Field for radius, or empty if using a fixed radius

shape¶: Kernel shape

source¶: Point feature source

weightField¶: Field name for weighting field, or empty if not using weights

RasterIoError = 4¶

class Result¶: Bases: int

Success = 0¶

addFeature(self, feature: QgsFeature) → QgsKernelDensityEstimation.Result[source]¶

Adds a single feature to the KDE surface. prepare() must be called before adding features.

See also

prepare()

See also

finalise()

Parameters:: feature (QgsFeature)
Return type:: QgsKernelDensityEstimation.Result

finalise(self) → QgsKernelDensityEstimation.Result[source]¶

Finalises the output file. Must be called after adding all features via addFeature().

See also

prepare()

See also

addFeature()

Return type:: QgsKernelDensityEstimation.Result

prepare(self) → QgsKernelDensityEstimation.Result[source]¶

Prepares the output file for writing and setups up the surface calculation. This must be called before adding features via addFeature().

See also

addFeature()

See also

finalise()

Return type:: QgsKernelDensityEstimation.Result

run(self) → QgsKernelDensityEstimation.Result[source]¶

Runs the KDE calculation across the whole layer at once. Either call this method, or manually call run(), addFeature() and finalise() separately.

Return type:: QgsKernelDensityEstimation.Result