如何使用d3.domain从JSON文件的多个列中获取d3.min和d3.max？

Question

这是我正在使用的JSON文件，我想使用ysec.domain（[d3.min（data，function（d）} {return（三列“ male”，“ female”和“ both “）}），d3.max（数据，函数（d）{return（” male“，” female“和” both“这三列的最大值）}）））; 无论如何，我是否要将最小值设置为三列中的最小值：“男性”，“女性”和“两者”，这也适用于最大值？

[{"year":"1960","male":"61.7","female":"65.7","both":"63.7","rankmale":"47","rankfemale":"50","rankall":"45"},
{"year":"1970","male":"65.4","female":"70.2","both":"67.7","rankmale":"45","rankfemale":"45","rankall":"44"},
{"year":"1980","male":"68.9","female":"74.2","both":"71.5","rankmale":"33","rankfemale":"36","rankall":"29"},
{"year":"1990","male":"71.9","female":"76.9","both":"74.3","rankmale":"28","rankfemale":"30","rankall":"30"},
{"year":"2000","male":"76.1","female":"80.1","both":"78.1","rankmale":"11","rankfemale":"24","rankall":"15"},
{"year":"2011","male":"80.1","female":"84.6","both":"82.3","rankmale":"6","rankfemale":"8","rankall":"5"}]

Answer 1

在您的情况下，您实际上不需要考虑both列，因为它是male和female列的平均值。我能想到的解决问题的最简单方法就是这样

var max = d3.max(data, function(d){
    return (d.male < d.female) ? d.female : d.male;
});

var min = d3.min(data, function(d){
    return (d.male < d.female) ? d.male : d.female;
});

Answer 2

幸运的是，在这种情况下您不需要两者，但如果需要，您可以使用 andMath.max()函数Math.min()来获取多个值的最大值或最小值。因此，您的最大值和最小值可能如下所示：

var max = d3.max(data, function(d){
    Math.max(d.male, d.female, d.both);
});
var max = d3.min(data, function(d){
    Math.min(d.male, d.female, d.both);
});

和函数适用于您想要使用的任意数量的列Math.max()。Math.min()