最近几年来，地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持，如城市管理、区划、环境整治等等，地理信息成为信息时代重要的组成部分之一； “数字地球”概念的提出，更进一步推动了作为其技术支撑的GIS的发展。 与此同时，一些学者致力于相关的理论研究，如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面，并且这两个方面构成了相互促进的发展过程。
1.7.1. SVG Ellipse- ¶ Example 1 ¶
Element is used to create an ellipse: An ellipse is very similar to a circle. The difference is that the ellipse has different x and y radii, while the x and y radii of the circle are the same:
Here is the SVG code:
Example
<svgxmlns="http://www.w3.org/2000/svg"version="1.1"><ellipsecx="300"cy="80"rx="100"ry="50"style="fill:yellow;stroke:purple;stroke-width:2"/>svg> For Opera users: view the SVG file (right-click the SVG drawing preview source).
Code parsing:
-
The x coordinate of the center of the ellipse defined by the CX property
-
The y coordinate of the center of the ellipse defined by the CY property
-
Horizontal radius defined by the RX attribute
-
The vertical radius defined by the RY attribute
Example 2 ¶
The following example creates three superimposed ellipses:
Here is the SVG code:
Example
<svgxmlns="http://www.w3.org/2000/svg"version="1.1"><ellipsecx="240"cy="100"rx="220"ry="30"style="fill:purple"/><ellipsecx="220"cy="70"rx="190"ry="20"style="fill:lime"/><ellipsecx="210"cy="45"rx="170"ry="15"style="fill:yellow"/>svg> For Opera users: view the SVG file (right-click the SVG drawing preview source).
Example 3 ¶
The following example combines two ellipses (one yellow and one white):
Here is the SVG code:
Example
<svgxmlns="http://www.w3.org/2000/svg"version="1.1"><ellipsecx="240"cy="50"rx="220"ry="30"style="fill:yellow"/><ellipsecx="220"cy="50"rx="190"ry="20"style="fill:white"/>svg> For Opera users: view the SVG file (right-click the SVG drawing preview source).
-
1. Angularjs2
8
-
1. SVG tutorial
19
-
1.17. SVG gradient-Linear
-
1.20. SVG reference manual
-
1.14. SVG filter
-
1.5. SVG <rect>
-
1.18. SVG gradient-radioactivity
-
1.2. SVG introduction
-
1.10. SVG <polyline>
-
1.16. SVG Shadow
-
1.19. SVG instance
-
1.8. SVG <line>
-
1. Memcached
20
-
1. C# tutorial
61
-
1. Sqlite
47
-
2. Go
43
-
2. Docker
59
-
2. Vue3
19
-
2. Servlet
21
-
3. React
23
-
3. SOAP tutorial
10
-
3. Android
18
-
3. Mongodb
44
-
3. Kotlin
18
-
4. Lua
31
-
4. MySQL tutorial
35
-
4. Appml
12
-
5. Perl
45
-
5. Postgresql
41
-
web
15
-
5. Web Services tutorial
6
-
6. Ruby
42
-
6. Design-pattern
35
-
7. Django
18
-
7. Rust
22
-
6. WSDL tutorial
8
-
8. Foundation
39
-
9. Ios
43
-
8. Css3
26
-
9. Swift
44
-
11. HTML tutorial-(HTML5 Standard)
54
-
12. Http
6
-
13. Regex
6
-
14. Regexp
8
-
1. Introduction to geographic information system
6
-
2. From the Real World to the Bit World
3
-
3. Spatial Data Model
7
-
4. 空间参照系统和 地图投影
5
-
5. Data in GIS
3
-
6. Spatial data acquisition
2
-
7. Spatial Data Management
6
-
8. Spatial analysis
8
-
9. 数字地形模型（ DTM ）与地形分析
5
-
10. 空间建模与 空间决策支持
6
-
11. Spatial data representation and map making
6
-
12. 3S Integration Technology
5
-
13. 网络地理信息系统
3
-
14. Examples of Geographic Information System Application
8
-
15. Organization and Management of Geographic Information System Application Projects
9
-
16. Geographic Information system Software Engineering Technology
6
-
17. Geographic Information System Standards
3
-
18. Geographic Information System and Society
3
-
19. Earth Information Science and Digital Earth
3
Example 1 ¶
An ellipse is very similar to a circle. The difference is that the ellipse has different x and y radii, while the x and y radii of the circle are the same: Here is the SVG code: Example For Opera users: view the SVG file (right-click the SVG drawing preview source). Code parsing: The x coordinate of the center of the ellipse defined by the CX property The y coordinate of the center of the ellipse defined by the CY property Horizontal radius defined by the RX attribute The vertical radius defined by the RY attribute The following example creates three superimposed ellipses: Here is the SVG code: Example For Opera users: view the SVG file (right-click the SVG drawing preview source). The following example combines two ellipses (one yellow and one white): Here is the SVG code: Example For Opera users: view the SVG file (right-click the SVG drawing preview source). <svgxmlns="http://www.w3.org/2000/svg"version="1.1"><ellipsecx="300"cy="80"rx="100"ry="50"style="fill:yellow;stroke:purple;stroke-width:2"/>svg>
Example 2 ¶
<svgxmlns="http://www.w3.org/2000/svg"version="1.1"><ellipsecx="240"cy="100"rx="220"ry="30"style="fill:purple"/><ellipsecx="220"cy="70"rx="190"ry="20"style="fill:lime"/><ellipsecx="210"cy="45"rx="170"ry="15"style="fill:yellow"/>svg>
Example 3 ¶
<svgxmlns="http://www.w3.org/2000/svg"version="1.1"><ellipsecx="240"cy="50"rx="220"ry="30"style="fill:yellow"/><ellipsecx="220"cy="50"rx="190"ry="20"style="fill:white"/>svg>