d3.js curveStep()用法及代码示例

阶跃曲线插值器创造代表阶跃函数的垂直和水平线。为数据集中的每对点创建一条垂直线。对于每对点，垂直线位于两个点之间的中点x坐标。

用法:

d3.curveStep()

参数：此方法不接受任何参数

返回值：此方法不返回任何值。

范例1：

HTML

<!DOCTYPE html> 
<html> 
<meta charset="utf-8"> 
  
<head> 
    <script src= 
"https://cdnjs.cloudflare.com/ajax/libs/d3/4.2.2/d3.min.js"> 
    </script> 
</head> 
  
<body> 
    <h1 style="text-align:center; color:green;"> 
        GeeksforGeeks 
    </h1> 
    <center> 
        <svg id="gfg" width="200" height="200"></svg> 
    </center> 
      
    <script> 
        var data = [ 
            { x:0, y:0 }, 
            { x:1, y:3 }, 
            { x:2, y:15 }, 
            { x:5, y:15 }, 
            { x:6, y:1 }, 
            { x:7, y:5 }, 
            { x:8, y:1 }]; 
  
        var xScale = d3.scaleLinear() 
            .domain([0, 8]).range([25, 175]); 
        var yScale = d3.scaleLinear() 
            .domain([0, 20]).range([175, 25]); 
  
        var line = d3.line() 
            .x((d) => xScale(d.x)) 
            .y((d) => yScale(d.y)) 
  
            // curveStep is used 
            .curve(d3.curveStep); 
  
        d3.select("#gfg") 
            .append("path") 
            .attr("d", line(data)) 
            .attr("fill", "none") 
            .attr("stroke", "green"); 
  
        // Defining points 
        d3.select('#gfg') 
            .selectAll('circle') 
            .data(data) 
            .enter() 
            .append('circle') 
            .attr('cx', (d) => xScale(d.x)) 
            .attr('cy', (d) => yScale(d.y)) 
            .attr('r', 3); 
    </script> 
</body> 
  
</html>

输出：

范例2：

HTML

<!DOCTYPE html> 
<html> 
<meta charset="utf-8"> 
  
<head> 
    <script src= 
"https://cdnjs.cloudflare.com/ajax/libs/d3/4.2.2/d3.min.js"> 
    </script> 
</head> 
  
<body> 
    <h1 style="text-align:center; color:green;"> 
        GeeksforGeeks 
    </h1> 
    <center> 
        <svg id="gfg" width="200" height="200"></svg> 
    </center> 
      
    <script> 
        var points = [ 
            { xpoint:25, ypoint:150 }, 
            { xpoint:75, ypoint:85 }, 
            { xpoint:100, ypoint:115 }, 
            { xpoint:175, ypoint:25 }]; 
  
        var Gen = d3.line() 
            .x((p) => p.xpoint) 
            .y((p) => p.ypoint) 
            .curve(d3.curveStep); 
  
        d3.select("#gfg") 
            .append("path") 
            .attr("d", Gen(points)) 
            .attr("fill", "none") 
            .attr("stroke", "green"); 
              
        // Defining points 
        d3.select('#gfg') 
            .selectAll('circle') 
            .data(points) 
            .enter() 
            .append('circle') 
            .attr('cx', (d) => (d.xpoint)) 
            .attr('cy', (d) => (d.ypoint)) 
            .attr('r', 3); 
    </script> 
</body> 
  
</html>

输出：

相关用法

注：本文由纯净天空筛选整理自taran910大神的英文原创作品 D3.js curveStep() Method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。