Class: QgsScaleCalculator¶
- class qgis.core.QgsScaleCalculator¶
Bases:
sip.wrapper
Calculates scale for a given combination of canvas size, map extent, and monitor dpi.
QgsScaleCalculator(dpi: float = 0, mapUnits: QgsUnitTypes.DistanceUnit = QgsUnitTypes.DistanceMeters) Constructor
- Parameters
dpi – Monitor resolution in dots per inch
mapUnits – Units of the data on the map
QgsScaleCalculator(
QgsScaleCalculator
)Methods
Calculate the scale denominator
Calculate the distance between two points in geographic coordinates.
Calculate the image size in pixel (physical) units
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
- calculate(self, mapExtent: QgsRectangle, canvasWidth: float) float ¶
Calculate the scale denominator
- Parameters
mapExtent (QgsRectangle) –
QgsRectangle
containing the current map extentcanvasWidth (float) – Width of the map canvas in pixel (physical) units
- Return type
float
- 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) –
QgsRectangle
containing the current map extent- Return type
float
- calculateImageSize(self, mapExtent: QgsRectangle, scale: float) QSizeF ¶
Calculate the image size in pixel (physical) units
- Parameters
mapExtent (QgsRectangle) –
QgsRectangle
containing the current map extentscale (float) – Scale denominator, e.g. 1000.0 for a 1:1000 map
- Return type
QSizeF
- Returns
image size
New in version 3.24.
- dpi(self) float ¶
Returns the DPI (dots per inch) used in scale calculations.
See also
- Return type
float
- mapUnits(self) QgsUnitTypes.DistanceUnit ¶
Returns current map units
- Return type
- setDpi(self, dpi: float)¶
Sets the
dpi
(dots per inch) for the output resolution, to be used in scale calculations.See also
- Parameters
dpi (float) –
- setMapUnits(self, mapUnits: QgsUnitTypes.DistanceUnit)¶
Set the map units
- Parameters
mapUnits (QgsUnitTypes.DistanceUnit) – Units of the data on the map. Must match a value from the