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d3.js geoMtFlatPolarParabolic()用法及代码示例

d3.geoMtFlatPolarParabolic()函数给出McBryde-Thomas flat-polar抛物线假圆柱equal-area投影。

用法:

d3.geoMtFlatPolarParabolic()

参数:此方法不接受任何参数。

返回值:此方法根据给定的JSON数据创建MtFlatPolarParabolic()投影。

范例1:以下示例创建中心为(0,0)且不旋转的MtFlatPolarParabolic()世界投影。



HTML

<!DOCTYPE html>  
<html lang="en">  
  
<head>  
    <meta charset="UTF-8" />  
    <meta name="viewport" content="width=device-width,  
                initial-scale=1.0" />  
     <script src="https://d3js.org/d3.v4.js"> 
     </script>  
    <script src=  
        "https://d3js.org/d3-geo-projection.v2.min.js">  
    </script>  
</head>  
  
<body>  
    <div style="width:700px; height:600px;">  
        <svg width="700" height="550">  
        </svg>  
    </div>  
  
    <script>  
        var svg = d3.select("svg"),  
            width = +svg.attr("width"),  
            height = +svg.attr("height");  
  
        // MtFlatPolarParabolic projection  
        // Center(0, 0) and no rotation  
        var gfg = d3.geoMtFlatPolarParabolic() 
            .scale(width / 1.5 / Math.PI)  
            .rotate([0, 0])  
            .center([0, 0])  
            .translate([width / 2, height / 3])  
  
        // Loading the json data  
        // Used json file stored at  
        // https://raw.githubusercontent.com/epistler999/  
        // GeoLocation/master/world.json 
        d3.json("https://raw.githubusercontent.com/" 
            +"epistler999/GeoLocation/master/world.json",  
            function (data) {  
                // Draw the map  
                svg.append("g")  
                    .selectAll("path")  
                    .data(data.features)  
                    .enter().append("path")  
                    .attr("fill", "black")  
                    .attr("d", d3.geoPath()  
                        .projection(gfg)  
                    )  
                   .style("stroke", "#ffff")  
            })  
    </script>  
</body> 
</html> 

输出:

范例2:在以下示例中,我们将创建中心为(30,0)并相对于Y轴旋转30度的anti-clockwise的世界MtFlatPolarParabolic()投影。

HTML

<!DOCTYPE html>  
<html lang="en">  
  
<head>  
    <meta charset="UTF-8" />  
    <meta name="viewport" content="width=device-width,  
                initial-scale=1.0" />  
    <script src="https://d3js.org/d3.v4.js"></script>  
    <script src=  
      "https://d3js.org/d3-geo-projection.v2.min.js">  
    </script>  
</head>  
  
<body>  
    <div style="width:700px; height:600px;">  
        <svg width="700" height="550">  
        </svg>  
    </div>  
  
    <script>  
        var svg = d3.select("svg"),  
            width = +svg.attr("width"),  
            height = +svg.attr("height");  
  
        // Mt Flat Polar Parabolic() projection  
        // Center(30, 0) and 30 degree rotation  
        var gfg = d3.geoMtFlatPolarParabolic() 
            .scale(width / 1.5 / Math.PI)  
            .rotate([-30, 0])  
            .center([30, 0])  
            .translate([width / 2, height / 2])  
  
        // Loading the json data  
        // Used json file stored at  
        // https://raw.githubusercontent.com/epistler999/  
        // GeoLocation/master/world.json 
        d3.json("https://raw.githubusercontent.com/" 
            +"epistler999/GeoLocation/master/world.json",  
            function (data) {  
                // Draw the map  
                svg.append("g")  
                    .selectAll("path")  
                    .data(data.features)  
                    .enter().append("path")  
                    .attr("fill", "black")  
                    .attr("d", d3.geoPath()  
                        .projection(gfg)  
                    )  
                   .style("stroke", "#ffff")  
            })  
    </script>  
</body> 
  
</html> 

输出:




相关用法

注:本文由纯净天空筛选整理自epistler_999大神的英文原创作品 D3.js geoMtFlatPolarParabolic() Function。非经特殊声明,原始代码版权归原作者所有,本译文的传播和使用请遵循“署名-相同方式共享 4.0 国际 (CC BY-SA 4.0)”协议。