Class: QgsHeatmapRenderer

class qgis.core.QgsHeatmapRenderer

Bases: QgsFeatureRenderer

A renderer which draws points as a live heatmap

Methods

accept

param visitor:

clone

rtype:

Optional[QgsHeatmapRenderer]

colorRamp

Returns the color ramp used for shading the heatmap.

convertFromRenderer

param renderer:

convertSymbolRotation

convertSymbolSizeScale

create

Creates a new heatmap renderer instance from XML

dump

rtype:

str

maximumValue

Returns the maximum value used for shading the heatmap.

modifyRequestExtent

param extent:

radius

Returns the radius for the heatmap

radiusMapUnitScale

Returns the map unit scale used for the heatmap's radius

radiusUnit

Returns the units used for the heatmap's radius

renderFeature

param feature:

renderFeatureWithSymbol

Render the feature with the symbol using context.

renderQuality

Returns the render quality used for drawing the heatmap.

renderVertexMarker

render editing vertex marker at specified point

renderVertexMarkerPolygon

render editing vertex marker for a polygon

renderVertexMarkerPolyline

render editing vertex marker for a polyline

save

param doc:

saveRendererData

Saves generic renderer data into the specified element.

setColorRamp

Sets the color ramp to use for shading the heatmap.

setMaximumValue

Sets the maximum value used for shading the heatmap.

setRadius

Sets the radius for the heatmap

setRadiusMapUnitScale

Sets the map unit scale used for the heatmap's radius

setRadiusUnit

Sets the units used for the heatmap's radius

setRenderQuality

Sets the render quality used for drawing the heatmap.

setWeightExpression

Sets the expression used for weighting points when generating the heatmap.

startRender

param context:

stopRender

param context:

symbolForFeature

symbols

usedAttributes

param context:

weightExpression

Returns the expression used for weighting points when generating the heatmap.

accept(self, visitor: QgsStyleEntityVisitorInterface | None) bool
Parameters:

visitor (Optional[QgsStyleEntityVisitorInterface])

Return type:

bool

clone(self) QgsHeatmapRenderer | None
Return type:

Optional[QgsHeatmapRenderer]

colorRamp(self) QgsColorRamp | None

Returns the color ramp used for shading the heatmap.

Return type:

Optional[QgsColorRamp]

Returns:

color ramp for heatmap

See also

setColorRamp()

convertFromRenderer(renderer: QgsFeatureRenderer | None) QgsHeatmapRenderer | None
Parameters:

renderer (Optional[QgsFeatureRenderer])

Return type:

Optional[QgsHeatmapRenderer]

convertSymbolRotation(symbol: QgsSymbol | None, field: str | None)

Note

this function is used to convert old rotations expressions to symbol level DataDefined angle

convertSymbolSizeScale(symbol: QgsSymbol | None, method: Qgis.ScaleMethod, field: str | None)

Note

this function is used to convert old sizeScale expressions to symbol level DataDefined size

create(element: QDomElement, context: QgsReadWriteContext) QgsFeatureRenderer | None

Creates a new heatmap renderer instance from XML

Parameters:
Return type:

Optional[QgsFeatureRenderer]

dump(self) str
Return type:

str

maximumValue(self) float

Returns the maximum value used for shading the heatmap.

Return type:

float

Returns:

maximum value for heatmap shading. If 0, then maximum value will be automatically calculated.

modifyRequestExtent(self, extent: QgsRectangle, context: QgsRenderContext)
Parameters:
radius(self) float

Returns the radius for the heatmap

Return type:

float

Returns:

heatmap radius

See also

setRadius()

See also

radiusUnit()

radiusMapUnitScale(self) QgsMapUnitScale

Returns the map unit scale used for the heatmap’s radius

Return type:

QgsMapUnitScale

Returns:

map unit scale for heatmap’s radius

See also

radius()

See also

radiusUnit()

radiusUnit(self) Qgis.RenderUnit

Returns the units used for the heatmap’s radius

Return type:

Qgis.RenderUnit

Returns:

units for heatmap radius

See also

radius()

See also

setRadiusUnit()

renderFeature(self, feature: QgsFeature, context: QgsRenderContext, layer: int = -1, selected: bool = False, drawVertexMarker: bool = False) bool
Parameters:
Return type:

bool

renderFeatureWithSymbol(self, feature: QgsFeature, symbol: QgsSymbol | None, context: QgsRenderContext, layer: int, selected: bool, drawVertexMarker: bool)

Render the feature with the symbol using context. Use layer to specify the symbol layer, selected to specify if it should be rendered as selected and drawVertexMarker to specify if vertex markers should be rendered.

renderQuality(self) float

Returns the render quality used for drawing the heatmap.

Return type:

float

Returns:

render quality. A value of 1 indicates maximum quality, and increasing the value will result in faster drawing but lower quality rendering.

renderVertexMarker(self, pt: QPointF | QPoint, context: QgsRenderContext)

render editing vertex marker at specified point

renderVertexMarkerPolygon(self, pts: QPolygonF, rings: Iterable[QPolygonF] | None, context: QgsRenderContext)

render editing vertex marker for a polygon

renderVertexMarkerPolyline(self, pts: QPolygonF, context: QgsRenderContext)

render editing vertex marker for a polyline

save(self, doc: QDomDocument, context: QgsReadWriteContext) QDomElement
Parameters:
Return type:

QDomElement

saveRendererData(self, doc: QDomDocument, element: QDomElement, context: QgsReadWriteContext)

Saves generic renderer data into the specified element.

This method should be called in a subclass’ save() implementation in order to store all common base class properties in the DOM element.

Added in version 3.22.

setColorRamp(self, ramp: QgsColorRamp | None)

Sets the color ramp to use for shading the heatmap.

Parameters:

ramp (Optional[QgsColorRamp]) – color ramp for heatmap. Ownership of ramp is transferred to the renderer.

See also

colorRamp()

setMaximumValue(self, value: float)

Sets the maximum value used for shading the heatmap.

Parameters:

value (float) – maximum value for heatmap shading. Set to 0 for automatic calculation of maximum value.

See also

maximumValue()

setRadius(self, radius: float)

Sets the radius for the heatmap

Parameters:

radius (float) – heatmap radius

See also

radius()

See also

setRadiusUnit()

setRadiusMapUnitScale(self, scale: QgsMapUnitScale)

Sets the map unit scale used for the heatmap’s radius

Parameters:

scale (QgsMapUnitScale) – map unit scale for heatmap’s radius

See also

setRadius()

See also

setRadiusUnit()

setRadiusUnit(self, unit: Qgis.RenderUnit)

Sets the units used for the heatmap’s radius

Parameters:

unit (Qgis.RenderUnit) – units for heatmap radius

See also

radiusUnit()

See also

setRadius()

setRenderQuality(self, quality: int)

Sets the render quality used for drawing the heatmap.

Parameters:

quality (int) – render quality. A value of 1 indicates maximum quality, and increasing the value will result in faster drawing but lower quality rendering.

See also

renderQuality()

setWeightExpression(self, expression: str | None)

Sets the expression used for weighting points when generating the heatmap.

Parameters:

expression (Optional[str]) – point weight expression. If set to empty, all points are equally weighted.

startRender(self, context: QgsRenderContext, fields: QgsFields)
Parameters:
stopRender(self, context: QgsRenderContext)
Parameters:

context (QgsRenderContext)

symbolForFeature(self, feature: QgsFeature, context: QgsRenderContext) QgsSymbol | None

Note

symbolForFeature2 in Python bindings

Parameters:
Return type:

Optional[QgsSymbol]

symbols(self, context: QgsRenderContext) List[QgsSymbol]

Note

symbol2 in Python bindings

Parameters:

context (QgsRenderContext)

Return type:

List[QgsSymbol]

usedAttributes(self, context: QgsRenderContext) Set[str]
Parameters:

context (QgsRenderContext)

Return type:

Set[str]

weightExpression(self) str

Returns the expression used for weighting points when generating the heatmap.

Return type:

str

Returns:

point weight expression. If empty, all points are equally weighted.