Class: QgsScaleCalculator¶
-
class
qgis.core.
QgsScaleCalculator
(dpi: float = 0, mapUnits: QgsUnitTypes.DistanceUnit = QgsUnitTypes.DistanceMeters)¶ Bases:
sip.wrapper
Constructor
- Parameters
dpi – Monitor resolution in dots per inch
mapUnits – Units of the data on the map
QgsScaleCalculator(QgsScaleCalculator)
Calculates scale for a given combination of canvas size, map extent, and monitor dpi.
Enums
Methods
Calculate the scale denominator
Calculate the distance between two points in geographic coordinates.
Returns the DPI (dots per inch) used in scale calculations.
Returns current map units
Sets the
dpi
(dots per inch) for the output resolution, to be used in scale calculations.Set the map units
Signals
Attributes
-
calculate
(self, mapExtent: QgsRectangle, canvasWidth: float) → float¶ Calculate the scale denominator
- Parameters
mapExtent – QgsRectangle containing the current map extent
canvasWidth – Width of the map canvas in pixel (physical) units
- Returns
scale denominator of current map view, e.g. 1000.0 for a 1:1000 map.
-
calculateGeographicDistance
(self, mapExtent: QgsRectangle) → float¶ Calculate the distance between two points in geographic coordinates. Used to calculate scale for map views with geographic (decimal degree) data.
- Parameters
mapExtent – QgsRectangle containing the current map extent
-
mapUnits
(self) → QgsUnitTypes.DistanceUnit¶ Returns current map units
-
setDpi
(self, dpi: float)¶ Sets the
dpi
(dots per inch) for the output resolution, to be used in scale calculations.See also
-
setMapUnits
(self, mapUnits: QgsUnitTypes.DistanceUnit)¶ Set the map units
- Parameters
mapUnits – Units of the data on the map. Must match a value from the