d3.js areaRadial.defined()用法及代碼示例

D3.js中的areaRadial.defined()方法讓我們指定是否為給定數據點定義數據。使用此方法的參數指定的布爾值或函數針對每個點檢查該值。如果此方法返回true，則保留檢查的值，否則將其省略。

用法:

areaRadial.defined( data_point )

參數：該函數接受如上所述和以下描述的單個參數：

data_point:它是一個布爾值或用於檢查每個點的函數。

返回值：此方法返回一個布爾值。

下麵給出的是D3.js中areaRadial.defined()方法的一些示例：

範例1：

HTML

<!DOCTYPE html> 
<html> 
<head> 
  <script src= 
"https://d3js.org/d3.v5.min.js"> 
  </script> 
</head> 
<body> 
  <h1 style="text-align:center; 
             color:green;"> 
    GeeksforGeeks 
  </h1> 
  <h3 style="text-align:center;"> 
    D3.js | areaRadial.defined() Method 
  </h3> 
  <center> 
    <svg id="gfg" width="500" height="500"> 
      <g transform="translate(180,180)"></g> 
    </svg> 
  </center> 
  <script> 
    var data = [ 
      { x:10, y:1 }, 
      { x:15, y:3 }, 
      { x:20, y:5 }, 
      { x:25, y:7 }, 
      { x:30, y:9 }, 
      { x:35, y:11 }, 
      { x:40, y:13 }]; 
  
    var xScale = d3.scaleLinear() 
        .domain([0, 8]) 
        .range([25, 200]); 
    var yScale = d3.scaleLinear() 
        .domain([0, 20]) 
        .range([200, 25]); 
  
    var Gen = d3.areaRadial() 
      .angle(d => xScale(d.x / 3)) 
      .innerRadius(d => yScale(d.y / 2)) 
      .outerRadius(d => yScale(d.y)) 
      // Omitting 4th index 
      .defined((d, i) => (i != 4)); 
  
    d3.select("#gfg") 
      .select("g") 
      .append("path") 
      .attr("d", Gen(data)) 
      .attr("fill", "green") 
      .attr("stroke", "black"); 
  </script> 
</body> 
</html>

輸出：

範例2：

HTML

<!DOCTYPE html> 
<html> 
<head> 
  <script src= 
"https://d3js.org/d3.v5.min.js"> 
  </script> 
</head> 
<body> 
  <h1 style="text-align:center; 
             color:green;"> 
    GeeksforGeeks 
  </h1> 
  <h3 style="text-align:center;"> 
    D3.js | areaRadial.defined() Method 
  </h3> 
  <center> 
    <svg id="gfg" width="200" height="200"> 
      <g transform="translate(100,100)"></g> 
    </svg> 
  </center> 
  <script> 
    var points = [ 
      { x:0, y:0 }, 
      { x:2, y:3 }, 
      { x:4, y:1 }, 
      { x:6, y:8 }, 
      { x:8, y:17 }, 
      { x:10, y:15 }, 
      { x:12, y:20 }]; 
  
    var xScale = d3.scaleLinear() 
        .domain([0, 6]) 
        .range([0, 2 * Math.PI]); 
    var yScale = d3.scaleLinear() 
        .domain([0, 20]) 
        .range([90, 30]); 
  
    var Gen = d3.areaRadial() 
      .angle(d => xScale(d.x / 2)) 
      .innerRadius(d => yScale(d.y) / 2) 
      .outerRadius(d => yScale(d.y)) 
      // Omitting 2nd index 
      .defined((d, i) => (i != 2)); 
  
    d3.select("#gfg") 
      .select("g") 
      .append("path") 
      .attr("d", Gen(points)) 
      .attr("fill", "green") 
      .attr("stroke", "black"); 
  </script> 
</body> 
</html>

輸出：

相關用法

注：本文由純淨天空篩選整理自taran910大神的英文原創作品 D3.js areaRadial.defined() Method。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。