D3-无图出现

Question

I have a variable called final csv which looks like and is stored in a CSV format. The lines are separated by a \\n. I'm using the statement D3.csv.parse. Can anyone tell me why nothing appears on the page at all? :-

   String, Float
   value, 1
   value2, 2 



function generateGraph(finalcsv)
{
    var finaldata = finalcsv;
    var margin = {top: 20, right: 20, bottom: 30, left: 40},
        width = 960 - margin.left - margin.right,
        height = 500 - margin.top - margin.bottom;

    var formatPercent = d3.format(".0");

    var x = d3.scale.ordinal()
        .rangeRoundBands([0, width], .1, 1);

    var y = d3.scale.linear()
        .range([height, 0]);

    var xAxis = d3.svg.axis()
        .scale(x)
        .orient("bottom");

    var yAxis = d3.svg.axis()
        .scale(y)
        .orient("left")
        .tickFormat(formatPercent);

    var svg = d3.select(#body).append("svg")
        .attr("width", width + margin.left + margin.right)
        .attr("height", height + margin.top + margin.bottom)
      .append("g")
        .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

    console.log(finaldata);

    d3.csv.parse(finaldata, function(error, data) {

      data.forEach(function(d) {
        d.Float = +d.Float;
      });

      x.domain(data.map(function(d) { return d.String; }));
      y.domain([0, d3.max(data, function(d) { return d.Float; })]);

      svg.append("g")
          .attr("class", "x axis")
          .attr("transform", "translate(0," + height + ")")
          .call(xAxis);

      svg.append("g")
          .attr("class", "y axis")
          .call(yAxis)
        .append("text")
          .attr("transform", "rotate(-90)")
          .attr("y", 6)
          .attr("dy", ".71em")
          .style("text-anchor", "end")
          .text("Integer");

      svg.selectAll(".bar")
          .data(data)
        .enter().append("rect")
          .attr("class", "bar")
          .attr("x", function(d) { return x(d.String); })
          .attr("width", x.rangeBand())
          .attr("y", function(d) { return y(d.Float); })
          .attr("height", function(d) { return height - y(d.Float); });
    });

}

Answer 1

I quickly built an example which seems to work (or at least it shows something): http://jsfiddle.net/frXRW/2/

The first difference with the code you provided is that I didn't use the d3.csv.parse() function , I don't know if your problem comes from there but I suggest you take a look at the documentation if your problem comes from there: https://github.com/mbostock/d3/wiki/CSV

The second thing I changed, and that I suspect is the source of your problem, is that you forgot to put the #body identifier between "" , so it is considered as an object. Thus I just changed the following line:

var svg = d3.select(#body).append("svg")

to

var svg = d3.select("#body").append("svg")

If this was your problem, then I would recommend you to use the chrome javascript console as it gave the following error pointing exactly to the line above:

Uncaught SyntaxError: Unexpected identifier