zoukankan      html  css  js  c++  java
  • pyqtree

    pyqtree module

    API Documentation

    Classes

    class Index

    The top spatial index to be created by the user. Once created it can be populated with geographically placed members that can later be tested for intersection with a user inputted geographic bounding box. Note that the index can be iterated through in a for-statement, which loops through all all the quad instances and lets you access their properties.

     

    Ancestors (in MRO)

    • Index
    • pyqtree._QuadTree

    Methods

    def __init__(

    self, bbox, maxitems=10, maxdepth=20)

    Parameters:

    • bbox: The coordinate system bounding box of the area that the quadtree should keep track of, as a 4-length sequence (xmin,ymin,xmax,ymax)
    • maxmembers (optional): The maximum number of items allowed per quad before splitting up into four new subquads. Default is 10.
    • maxdepth (optional): The maximum levels of nested subquads, after which no more splitting occurs and the bottommost quad nodes may grow indefinately. Default is 20.
     

    def countmembers(

    self)

    Returns:

    • A count of the total number of members/items/nodes inserted into this quadtree and all of its child trees.
     

    def insert(

    self, item, bbox)

    Inserts an item into the quadtree along with its bounding box.

    Parameters:

    • item: The item to insert into the index, which will be returned by the intersection method
    • bbox: The spatial bounding box tuple of the item, with four members (xmin,ymin,xmax,ymax)
     

    def intersect(

    self, bbox)

    Intersects an input boundingbox rectangle with all of the items contained in the quadtree.

    Parameters:

    • bbox: A spatial bounding box tuple with four members (xmin,ymin,xmax,ymax)

    Returns:

    • A list of inserted items whose bounding boxes intersect with the input rectangle.

    Here are the examples of the python api pyqtree.Index taken from open source projects. By voting up you can indicate which examples are most useful and appropriate.

    2 Examples

    Example 1

    Project: joerd 
    Source File: index.py
    View license
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    def create(index_file, bbox, parse_fn, *parse_args):
        logger = logging.getLogger("index")
        idx = pyqtree.Index(bbox=bbox)
        n = 0
     
        with open(index_file, 'r') as f:
            files = yaml.load(f)
            for f in files:
                t = parse_fn(f, *parse_args)
                if t:
                    idx.insert(bbox=t.bbox.bounds, item=t)
                    n += 1
     
        logger.info("Created index with %d objects." % n)
        return idx

    Example 2

    Project: gtfslib-python 
    Source File: spatial.py
    View license
    1
    2
    3
    4
    5
    6
    7
    def __init__(self, D0):
        self._D0 = 1. * D0
        bbox = (-180, -90, 180, 90)
        self._spidx = pyqtree.Index(bbox)
        self._points = []
        self._clusters_by_item = None
        self._clusters = None
  • 相关阅读:
    设计模式(三)原型模式
    PageHelper在Mybatis中的使用
    设计模式(二) 单例模式
    设计模式(一)简单工厂、工厂方法和抽象工厂
    Java网络编程
    循环控制语句if 、for、case、while
    处理海量数据的grep、cut、awk、sed 命令
    shell脚本的输入以及脚本拥有特效地输出
    shell的变量以及常见符号
    shell的使用技巧
  • 原文地址:https://www.cnblogs.com/ExMan/p/10407643.html
Copyright © 2011-2022 走看看