d3.js node.sum()用法及代码示例

d3.js中的node.sum()函数用于评估特定节点的指定值函数。此函数的node.value属性包含指定函数返回的值。

用法:

node.sum(value);

参数：该函数接受如上所述和以下描述的单个参数：

value:这需要为每个节点评估一个函数。

返回值：此函数返回一个对象。

下面给出的是上面给出的函数的一些例子。

范例1：

HTML

<!DOCTYPE html>  
<html lang = "en">  
<head>  
    <meta charset = "UTF-8" />  
    <meta name = "viewport"
          path1tent = "width=device-width,  
                       initial-scale = 1.0"/>  
    <script src = 
"https://d3js.org/d3.v4.min.js"> 
    </script> 
</head>  
  
<body>  
    <script>  
       // Constructing a tree 
        var tree={ 
            name:"rootNode", // Root node 
            children:[ 
                { 
                    name:"child1", // Child of root node 
                    value:2 
                }, 
                { 
                    name:"child2", // Child of root node 
                    value:3, 
                    children:[ 
                        { 
                            name:"grandchild1", // Child of child2 
                            value:1, 
                            children:[ 
                                {name:"grand_granchild1_1",value:4},                               
                                // Child of grandchild1 
                                {name:"grand_granchild1_2",value:5}                      
                               // Child of grandchild1 
                            ] 
                        }, 
                        { 
                            name:"grandchild2", 
                            children:[ 
                                {name:"grand_granchild2_1"},   
                                // Child of grandchild2 
                                {name:"grand_granchild2_2"}   
                                // Child of grandchild2 
                            ] 
                        }, 
                    ] 
                } 
            ] 
        }; 
  
        var obj = d3.hierarchy(tree); 
        var grandchild2=obj.children[1].children[1]; 
          
        var sum=obj.sum(d=>d.value); 
        console.log(sum); 
        console.log("The sum of value is:",sum.value); 
    </script>  
</body>  
</html>

输出：

范例2：

HTML

<!DOCTYPE html>  
<html lang = "en">  
<head>  
    <meta charset = "UTF-8" />  
    <meta name = "viewport"
          path1tent = "width=device-width,  
                       initial-scale = 1.0"/>  
    <script src = 
"https://d3js.org/d3.v4.min.js"> 
    </script> 
</head>  
<body>  
    <script>  
    // Constructing a tree 
        var tree={ 
            name:"rootNode", // Root node 
            children:[ 
                {value:1}, 
                {value:2}, 
                {value:3}, 
                {value:4}, 
                {value:5}, 
                {value:6}, 
            ] 
        }; 
  
        var obj = d3.hierarchy(tree); 
          
        var sum=obj.sum(d=>d.value*12); 
        // 1 + 2 + 3 + 4 + 5 + 6 = 21*12=252 
        console.log(sum); 
        console.log("The value is:",sum.value); 
    </script>  
</body>  
</html>

输出：

相关用法

注：本文由纯净天空筛选整理自tarun007大神的英文原创作品 D3.js node.sum() Function。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。