未捕获到的TypeError：无法读取d3.js数据未定义的属性“轴”

Question

我收到以下错误消息

Uncaught TypeError: Cannot read property 'axis' of undefined

在此行中被呼出：

xAxis = d3.svg2.axis().scale(x).tickSize(-height).tickSubdivide(true)

令我感到困惑的是，这是我第一次在svg的先前函数中编写此行（而不是像此处所述的svg2）时，该行工作得很好

这是我的HTML：

<div id="svg"></div>

<div id="svg2"></div>

<div id="svg3"></div>

我的CSS：

    body {
  font: 10px sans-serif;
  margin: 0;
}

path.line {
  fill: none;
  stroke: #666;
  stroke-width: 1.5px;
}

path.area {
  fill: #e7e7e7;
}

.axis {
  shape-rendering: crispEdges;
}


.x.axis line {
  stroke: #fff;
}

.x.axis .minor {
  stroke-opacity: .5;
}

.x.axis path {
  display: none;
}

.y.axis line, .y.axis path {
  fill: none;
  stroke: #000;
}

.guideline {
  margin-right: 100px;
  float: right;
}

这是我的JavaScript：

function totalFatalitiesLineGraph() {


var margin = {top: 80, right: 80, bottom: 80, left: 80},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;


var svg2 = d3.select("#svg2").append("svg2")
              .attr("width", width)
              .attr("height", height);


//var parse = d3.time.format("%b %Y").parse;
var parse = d3.time.format("%Y").parse; 

// Scales and axes. Note the inverted domain for the y-scale: bigger is 
up!
var x = d3.time.scale().range([0, width]),
    y = d3.scale.linear().range([height, 0]),
    xAxis = d3.svg2.axis().scale(x).tickSize(- 
    height).tickSubdivide(true),
    yAxis = d3.svg2.axis().scale(y).ticks(4).orient("right");

// An area generator, for the light fill.
var area = d3.svg2.area()
    .interpolate("monotone")
    .x(function(d) { return x(d.date); })
    .y0(height)
    .y1(function(d) { return y(d.fatalities); }); 

// A line generator, for the dark stroke.
var line = d3.svg2.line()
    .interpolate("monotone")
    .x(function(d) { return x(d.date); })
    .y(function(d) { return y(d.fatalities); });


// Parse dates and numbers. We assume israel are sorted by date.
function type(d) {
  d.country = d.country;
  d.date = parse(d.date);
  d.fatalities = +d.fatalities
  return d;
};



var data = d3.csv("static/data/israel/fatalities_linechart.csv", type, 
function(error, data) {
    console.log(data);

  var israel = data.filter(function(d) {
    return d.country == "Israel";
  });


  x.domain([unitedStates[0].date, unitedStates[unitedStates.length - 
  1].date]);
  y.domain([0, d3.max(egypt, function(d) { return d.fatalities; 
  })]).nice();

  //x.domain([israel[0].date, israel[israel.length - 1].date]);
  //y.domain([0, d3.max(israel, function(d) { return d.incidents; 
   })]).nice();

  // Add an SVG element with the desired dimensions and margin.
  var svg2 = d3.select("svg2")
      .attr("width", width + margin.left + margin.right)
      .attr("height", height + margin.top + margin.bottom)
      .append("g")
      .attr("transform", "translate(" + margin.left + "," + margin.top 
   + ")")

  // Add the clip path.
  svg2.append("clipPath")
      .attr("id", "clip")
      .append("rect")
      .attr("width", width)
      .attr("height", height);

  // Add the x-axis.
  svg2.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis);

  // Add the y-axis.
  svg2.append("g")
      .attr("class", "y axis")
      .attr("transform", "translate(" + width + ",0)")
      .call(yAxis);


  var colors = d3.scale.category10();

  svg2.selectAll('.line')
    .data([israel, unitedStates, iran, saudiArabia, turkey, egypt, 
   syria, lebanon, jordan, palestine]) 
    .enter()
      .append('path')
        .attr('class', 'line')
        .style('stroke', function(d) {
          return colors(Math.random() * 50);
        })
        .attr('clip-path', 'url(#clip)')
        .attr('d', function(d) {
          return line(d);
        })

  /* Add 'curtain' rectangle to hide entire graph */
  var curtain = svg2.append('rect')
    .attr('x', -1 * width)
    .attr('y', -1 * height)
    .attr('height', height)
    .attr('width', width)
    .attr('class', 'curtain')
    .attr('transform', 'rotate(180)')
    .style('fill', '#ffffff')

  /* Optionally add a guideline */
  var guideline = svg2.append('line')
    .attr('stroke', '#333')
    .attr('stroke-width', 0)
    .attr('class', 'guide')
    .attr('x1', 1)
    .attr('y1', 1)
    .attr('x2', 1)
    .attr('y2', height)

  /* Create a shared transition for anything we're animating */
  var t = svg2.transition()
    .delay(750)
    .duration(6000)
    .ease('linear')
    .each('end', function() {
      d3.select('line.guide')
        .transition()
        .style('opacity', 0)
        .remove()
    });

  t.select('rect.curtain')
    .attr('width', 0);
  t.select('line.guide')
    .attr('transform', 'translate(' + width + ', 0)')

  d3.select("#show_guideline").on("change", function(e) {
    guideline.attr('stroke-width', this.checked ? 1 : 0);
    curtain.attr("opacity", this.checked ? 0.75 : 1);
  })

});

}; 

它在以前的功能中工作得很好，除了引用不同的csv形式外，该功能几乎与此功能相同。有人知道这是怎么回事吗？