D3.js curveBasisClosed() Method

Last Updated : 14 Sep, 2020

The basis curve interpolator produces cubic basis splines where the points provided to the generators are used as control points. This is a closed variant which adds a curve between the first and last point in the dataset.

Syntax:

d3.curveBasisClosed()

Parameters: This method does not accept any parameters.

Return Value: This method does not return any value.

Example 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)) 
  
            // curveBasisClosed is used 
            .curve(d3.curveBasisClosed); 
  
        d3.select("#gfg") 
            .append("path") 
            .attr("d", line(data)) 
            .attr("fill", "none") 
            .attr("stroke", "green"); 
    </script> 
</body> 
  
</html> 

Output:

Example 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.curveBasisClosed); 
  
        d3.select("#gfg") 
            .append("path") 
            .attr("d", Gen(points)) 
            .attr("fill", "none") 
            .attr("stroke", "green"); 
    </script> 
</body> 
  
</html> 