Question

以下是来自tsv文件的示例数据：

college dept    year
College of Education, Health & Human Development    Education.  2011
College of Letters & Science    Earth Sciences. 2010
College of Letters & Science    Microbiology & Immunology.  2004
College of Letters & Science    Ecology.    1984
College of Letters & Science    Chemistry & Biochemistry.   2008
College of Letters & Science    Mathematical Sciences.  2011
College of Agriculture  Land Resources & Environmental Sciences.    2009
College of Agriculture  Agricultural Economics & Economics. 1996
College of Letters & Science    English.    2007
College of Letters & Science    Cell Biology & Neuroscience.    2011
College of Agriculture  Land Resources & Environmental Sciences.    2012
Graduate School Intercollege Programs for Science Education.    2012
Graduate School Intercollege Programs for Science Education.    2011
College of Engineering  Mechanical & Industrial Engineering.    2007
College of Engineering  Industrial Engineering. 2005
College of Agriculture  Agricultural Economics & Economics. 1986
College of Nursing  Nursing.    2007
College of Letters & Science    Microbiology & Immunology.  2006
College of Agriculture  Agricultural Economics & Economics. 1974

我正在使用d3.nest如下：

  var deptYearCount = d3.nest()
    .key(function(d) { return d.college;} )
    .key(function(d) { return d.dept })
    .key(function(d) { return d.year })
    .rollup(function(leaves) { return leaves.length;})
        .entries(dataset);

我正在尝试按年份计算半径圆圈：

svg.selectAll(".dot")
      .data(deptYearCount)
    .enter().append("circle")
      .attr("class", "dot")
      .attr("r", function(d) { return d.values*1.5;})
      .style("opacity", 0.3)
      .style("fill", "#e31a1c" )
      .attr("cx", function(d) { return x(d.year); })
      .attr("cy", function(d) { return y(d.dept); });

d.values返回NaN解析r属性。我试过以各种方式获得这个价值，但它没有用。

Answer 1

d.values是一个数组。

所以不要这样：

.attr("r", function(d) { return d.values*1.5;})

你应该这样做，因为你想根据年份计算半径：

.attr("r", function(d) {return d.values.length*1.5;})

捕获来自d3.nest的leaves.length值

1 个答案: