Google Earth Engine（gee）中的Feature

た入场券 2021-07-25 14:30 522阅读 0赞

**目录**

ee.Feature()

Feature.select()

Feature中的set、setMulti

Feature.transform()

Feature.centroid/simplify/bounds/convexHull/buffer()

Feature.union/intersection/difference/symmetricDifference()

Feature中计算面积:area()、周长:perimeter()

--------------------

# ee.Feature()  #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70][]

var geometry_tianfu= ee.Geometry.Polygon([[[104.06431420192233, 30.65820626544307],
                                              [104.06455023631564, 30.656581911340815],
                                              [104.06714661464206, 30.656581911340815],
                                              [104.06733973369113, 30.658372391028514]]])
                  
    var properties_tianfu=  {
              "name": "天府广场",
              "location": "成都",
              "system:index": "0"
            }     
            
    var feature_tianfu =ee.Feature( geometry_tianfu,properties_tianfu);
    print(feature_tianfu)
    
    Map.centerObject(feature_tianfu)
    Map.addLayer(feature_tianfu)

# Feature.select() #

提取出想要的属性，并给属性名改名

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 1][]

var geometry_tianfu= ee.Geometry.Polygon([[[104.06431420192233, 30.65820626544307],
                                              [104.06455023631564, 30.656581911340815],
                                              [104.06714661464206, 30.656581911340815],
                                              [104.06733973369113, 30.658372391028514]]])
                  
    var properties_tianfu=  {
              "name": "天府广场",
              "location": "成都",
              "system:index": "0"
            }     
            
    var feature_tianfu =ee.Feature( geometry_tianfu,properties_tianfu);
    print(feature_tianfu)
    print(feature_tianfu.select(["name"]))
    print(feature_tianfu.select(["name"],["名称"]))

# Feature中的set、setMulti #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 2][]

var geometry_tianfu= ee.Geometry.Polygon([[[104.06431420192233, 30.65820626544307],
                                              [104.06455023631564, 30.656581911340815],
                                              [104.06714661464206, 30.656581911340815],
                                              [104.06733973369113, 30.658372391028514]]])
                  
    var properties_tianfu=  {
              "name": "天府广场",
              "location": "成都",
              "system:index": "0"
            }     
            
    var feature_tianfu =ee.Feature( geometry_tianfu,properties_tianfu);
    print(feature_tianfu)
    print(feature_tianfu.set('location','chengdu'))
    print(feature_tianfu.setMulti({'name':'chengdu','location':"tianfuguangchang"}))

# Feature.transform() #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 3][]

print("myGeometry",myGeometry)
    
    var feature=ee.Feature(myGeometry)
    print("feature",feature)
    
    var feature_transform=feature.transform('EPSG:3857',ee.ErrorMargin(100))
    print("feature_transform",feature_transform)
    
    print(ee.Geometry(feature.geometry()).projection())
    print(ee.Geometry(feature_transform.geometry()).projection())

# Feature.centroid/simplify/bounds/convexHull/buffer() #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 4][]

![20201124224925653.png][]![20201124224940852.png][]![20201124224949703.png][]![20201124224957737.png][]![20201124225004960.png][]

# Feature.union/intersection/difference/symmetricDifference() #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 5][]

![20201124233138280.png][]![20201124233228980.png][]![20201124233240133.png][]![20201124233300924.png][]![20201124233313445.png][]

var feature1 =ee.Feature(ee.Geometry.Polygon(
                [[[103.43534679370603, 31.17014003162498],
                  [102.90800304370603, 30.45777180538538],
                  [103.71549816089353, 29.911716302186857],
                  [104.48454112964353, 30.329839651564306],
                  [104.03410167651853, 31.014908583940628]]]))
    var feature2 = ee.Feature(ee.Geometry.Polygon(
                [[[104.44608898120603, 31.04785765490257],
                  [103.91325206714353, 30.63281369239727],
                  [104.30326671558103, 29.959319376777437],
                  [105.34147472339353, 30.044947475833734]]]));
                  
    
    Map.centerObject(feature1)
    Map.addLayer(feature1,{color:"00ffff"},"feature1")
    Map.addLayer(feature2,{color:"32CD32"},"feature2")
    
    
    Map.addLayer(feature1.union((feature2)),{},"union")
    Map.addLayer(feature1.intersection((feature2)),{},"intersection")
    Map.addLayer(feature1.difference((feature2)),{},"difference")
    Map.addLayer(feature1.symmetricDifference((feature2)),{},"symmetricDifference")

# Feature中计算面积:area()、周长:perimeter() #

*  area()：面积函数
 *  perimeter()：周长函数

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 6][]

print(sichuan)
    print(sichuan.first())
    print("面积",ee.Feature(sichuan.first()).area())
    print("周长",ee.Feature(sichuan.first()).perimeter())

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[20201124224925653.png]: https://img-blog.csdnimg.cn/20201124224925653.png
[20201124224940852.png]: https://img-blog.csdnimg.cn/20201124224940852.png
[20201124224949703.png]: https://img-blog.csdnimg.cn/20201124224949703.png
[20201124224957737.png]: https://img-blog.csdnimg.cn/20201124224957737.png
[20201124225004960.png]: https://img-blog.csdnimg.cn/20201124225004960.png
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[20201124233138280.png]: https://img-blog.csdnimg.cn/20201124233138280.png
[20201124233228980.png]: https://img-blog.csdnimg.cn/20201124233228980.png
[20201124233240133.png]: https://img-blog.csdnimg.cn/20201124233240133.png
[20201124233300924.png]: https://img-blog.csdnimg.cn/20201124233300924.png
[20201124233313445.png]: https://img-blog.csdnimg.cn/20201124233313445.png
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