visvalingamwyatt 0.1.2

使用

>>>importvisvalingamwyattasvw>>>points=[(1,2),(2,3),(3,4),...]>>>vw.simplify(points)[(1,2),(3,4),...]

点可以是任何类似于Sequence的对象（list，tuple，a 公开__iter__方法的自定义类）。

测试不同的方法和阈值：

simplifier=vw.Simplifier(points)# Simplify by percentage of points to keepsimplifier.simplify(ratio=0.5)# Simplify by giving number of points to keepsimplifier.simplify(number=1000)# Simplify by giving an area thresholdsimplifier.simplify(threshold=0.01)

使用Geodata的缩写：

importvisvalingamwyattasvwfeature={"properties":{"foo":"bar"},"geometry":{"type":"Polygon","coordinates":[...]}}# returns a copy of the geometry, simplified (keeping 90% of points)vw.simplify_geometry(feature['geometry'],ratio=0.90)# returns a copy of the feature, simplified (using an area threshold)vw.simplify_feature(feature,threshold=0.90)

命令行工具vwsimplify可用于简化geojson 文件：

# Simplify using a ratio of points
vwsimplify --ratio 0.90 in.geojson -o simple.geojson

# Simplify using the number of points to keep
vwsimplify --number 1000 in.geojson -o simple.geojson

# Simplify using a minimum area
vwsimplify --threshold 0.001 in.geojson -o simple.geojson

为安装Fiona 简化任何地理数据层的附加功能。

许可证

麻省理工学院