1.导入必要的模块导入必要的模块:从qgis.core导入QgsDistanceArea,用于计算距离;从 processing.core导入ProcessingAlgorithm,用于定义算法。 2.定义算法类定义算法类:DistanceBetweenPointsAlgorithm继承自 ProcessingAlgorithm,实现算法的逻辑。 3.初始化算法参数初始化算法参数:通过initAlgorithm方法添加算法参数,包括两个点和一...
定义一个类并初始化一些属性、canvasPressEvent用于标点、calculate_distance用于计算距离 from qgis.gui import QgsMapTool from qgis.PyQt.QtCore import Qt from qgis.core import QgsDistanceArea class MeasureDistanceTool(QgsMapTool): def __init__(self, canvas, distance_label): super(MeasureDistanceTool, s...
Calculate the centroid of a polygon feature:centroid($geometry) Calculate the bounding box of a feature:bounds($geometry) Calculate the distance between two points:distance(point_a, point_b) Calculate the area of a polygon feature in square kilometers:$area / 1000000 Calculate the perimeter of ...
Calculate Distance Matrices Distances between points A and B are calculated by listing all possible routes with times and distances (many-to-many scenarios). Optimize your route planning and increase your efficiency and profitability. Matrix Analysis (also Portfolio Analysis, Boston or BGC Matrix) In...
())self.distance=self.calculate_distance()ifself.distance_label:self.distance_label.setText(f"距离: {self.distance:.2f} 米")self.start_point=Noneself.end_point=Nonedefcalculate_distance(self):ifself.start_pointandself.end_point:returnself.distance_area.measureLine(self.start_point,self...
consulting the marginal notes to see what a little circle with a flag on it signifies and what’s the difference between a pictogram of an airplane with a circle around it and one without, issuing small profound ‘Hmmmm’s’ and nodding my head gravely without having the faintest idea why....
(parameters, self.OUTPUT)) coordTransform = None # Calculate with: # 0 - layer CRS # 1 - project CRS # 2 - ellipsoidal self.distance_area = QgsDistanceArea() if method == 2: self.distance_area.setSourceCrs(source.sourceCrs(), context.transformContext()) self.distan...
The boundary of the Voronoi diagram is the min/max extent of the points in the source layer.The algorithm used to calculate the edges and nodes starts with tangents at the midpoints of lines between each point. The closest tangent is assumed to be a border and intersections to the border...
points and another set of destination points, we can calculate the shortest path between each origin-destination pairs and find out the travel distance/time between them. Such analysis is useful to locate the closest facility to any given point. For example, a logistics company may use this ...
Distance between points- This is the stepping distance between rendered points. The value must be greater than 0. Distance units- The unit of distance measurements of the above parameters. Arc wedge In essence this takes a wedge of a donut shape. The parameters are similar toPie wedgeandDonut...