javascript - D3 散点图的 Y 轴未缩放/更改

Question

我制作了一个散点图，它根据下拉框中选择的 Y 轴变量动态变化(x 轴是固定的)。但是，Y 轴不会根据下拉框中选择的变量进行缩放/更改。

// select svg canvas
var m = [20, 20, 30, 20],  // margins
    w = 1100-m[1]-m[3],    // width
    h = 650-m[0]-m[2],     // height
    xcol = 0,              // active x column
    ycol = 1;              // active y column

// create svg element, adjusted by margins
var svg = d3.select('#chart')
  .append("g")
  .attr("transform", "translate(" + m[3] + "," + m[0] + ")");

// add the tooltip area to the webpage
var tooltip = d3.select("body").append("div")
    .attr("class", "tooltip")
    .style("opacity", 0);

// load data from csv file
d3.csv('nbaWins.csv', function(data) {

  // get columns of csv, mark excluded columns
  var columns = d3.keys( data[0] ),
      excluded = ['Team'];

  // get quantitative dimensions
  var dimensions = _(columns)
    .difference(excluded);

  // extents for each dimension
  var extents = _(dimensions)
    .map(function(col) {
      return [0, d3.max(data, function(d) { return parseFloat(d[col]) })]
    });

  // x & y variables
  var x = d3.scale.linear().domain(extents[xcol]).range([0, w - 50]),
      y = d3.scale.linear().domain(extents[ycol]).range([h, 0]),
      xAxis = d3.svg.axis().scale(x).orient("bottom"),
      yAxis = d3.svg.axis().scale(y).orient("left");

  // color scale (change colors later)
  var color = {
    "ATL": '#ff9896',
    "BOS": '#ff9896',
    "BKN": '#ff9896',
    "CHA": '#ff9896',
    "CHI": '#ff9896',
    "CLE": '#ff9896',
    "DAL": '#ff9896',
    "DEN": '#ff9896',
    "DET": '#ff9896',
    "GSW": '#ff9896',
    "HOU": '#ff9896',
    "IND": '#ff9896',
    "LAC": '#ff9896',
    "LAL": '#ff9896',
    "MEM": '#ff9896',
    "MIA": "#ff9896",
    "MIL": '#ff9896',
    "MIN": '#ff9896',
    "NO" : '#ff9896',
    "NYK": '#ff9896',
    "OKC": '#ff9896',
    "ORL": '#ff9896',
    "PHI": '#ff9896',
    "PHO": '#ff9896',
    "POR": '#ff9896',
    "SAC": '#ff9896',
    "SAS": '#ff9896',
    "TOR": '#ff9896',
    "UTA": '#ff9896',
    "WAS": '#ff9896'
  };

  // create x axis
  svg.append("g")
    .attr("class", "x axis")
    .attr("transform", "translate(0," + h + ")")
    .call(xAxis)
  .append("text")
    .attr("class", "label")
    .attr("x", w - 40)
    .attr("y", -6)
    .style("text-anchor", "end")
    .text("Wins");

  // create y axis
  svg.append("g")
      .attr("class", "y axis")
      .call(yAxis);

  // bind data to chart
  svg.selectAll('circle')
     .data(data)
   .enter().append('circle')
     .attr("fill", function(d) { return color[d.Team]; })
     .attr("cx", function(d) { return x(d[dimensions[xcol]]); })
     .attr("cy", function(d) { return y(d[dimensions[ycol]]); })
     .attr("r", 5) //backup
     .on("mouseover", function(d) {
          tooltip.transition().duration(200).style("opacity", .9);
          tooltip.html(d["Team"] + "<br/> (" + d[dimensions[xcol]] 
          + ", " + d[dimensions[ycol]] + ")")
               .style("left", d + "px")
               .style("top", d + "px");
      })
      .on("mouseout", function(d) {
          tooltip.transition()
               .duration(500)
               .style("opacity", 0);
      });

  // change x axis data (may not need: x axis is static)
  function xaxis(i) {
    xcol = i;
    x.domain(extents[i]);
    svg.selectAll('circle')
      .transition()
      .ease('linear')
      .duration(1000)
      .attr("cx", function(d) { return x(d[dimensions[0]]); })
      .attr("cy", function(d) { return y(d[dimensions[ycol]]); });
  };

  // change y axis data
  function yaxis(i) {
    ycol = i;
    y.domain(extents[i]);
    svg.selectAll('circle')
      .transition()
      .ease('linear')
      .duration(1000)
      .attr("cx", function(d) { return x(d[dimensions[0]]); })
      .attr("cy", function(d) { return y(d[dimensions[i]]); });
  };

  // create dropdowns to change y axes
  d3.select("#yaxis")
    .selectAll("option")
    .data(dimensions)
    .enter().append("option")
      .attr("value", function(d,i) { return i; })
      .text(function(d) { return d; })
      .each(function(d,i) {
        if (i == ycol) d3.select(this).attr("selected", "yes");
      });

  d3.select("#yaxis")
      .on("change", function() { yaxis(this.selectedIndex) });
  window.data = data;

});

这是我尝试更改 Y 变量时收到的控制台错误:

NotFoundError: DOM Exception 8: An attempt was made to reference a Node in a context where it does not exist.

关于如何解决这个问题有什么想法吗？任何帮助将不胜感激。

Answer 1

您已经设置了 y 的域，但尚未用它重绘轴:

// change y axis data
  function yaxis(i) {
    ycol = i;
    y.domain(extents[i]);

    // update y axis
    svg.selectAll("g.y.axis")
      .call(yAxis);

    svg.selectAll('circle')
      .transition()
      .ease('linear')
      .duration(1000)
      .attr("cx", function(d) { return x(d[dimensions[0]]); })
      .attr("cy", function(d) { return y(d[dimensions[i]]); });
  };

示例 here .