D3.js band.rangeRound()函数

band.rangeRound()函数用于将刻度范围设置为指定的二元素数组，同时它还将舍入设置为 true。

句法：

band.rangeRound([range]) 

参数：此函数接受上面给出的单个参数，如下所述：

• range：此参数接受一个二元素数字数组。

返回值：此函数不返回任何内容。

下面给出了上面给出的函数的几个例子。

示例 1：

 
 
 
     
     
    
    
      
 
 
     
    // Creating the band scale with
    // specified domain and range.
        var band = d3.scaleBand()
                    .domain([10, 20, 30, 40, 50])
                    .range([0, 1]);
  
        console.log("Without rangeRound function:");
        console.log("band(10): ", band(10));
        console.log("band(20): ", band(20));
        
        console.log("With rangeRound function:");
        
        var band = d3.scaleBand()
                    .domain([10, 20, 30, 40, 50])
                    .rangeRound([0, 1]);
        
        console.log("band(10): ", band(10));
        console.log("band(20): ", band(20));
     
 

输出：

示例 2：

 
 
 
     
     
    
    
      
 
 
     
    // Creating the band scale with
     // specified domain and range.
        var band = d3.scaleBand()
                    .domain([1, 2, 3, 4])
        // When range is in string
                    .range(["0", "10"]);
        console.log("Without rangeRound function:");
        console.log("band(1): ", band(1));
        console.log("band(2): ", band(2));
        
        console.log("With rangeRound function:");
        
        var band = d3.scaleBand()
                    .domain([1, 2, 3, 4, 5])
                    .rangeRound(["0", "10"]);
        
        console.log("band(1): ", band(1));
        console.log("band(2): ", band(2));
     
 

输出：