CODEWITHSUNDEEP
d3.js
andyopayne
andyopayne

Reputation: 1368

D3 Parsing Error

This is likely a very easy question (but I'm new to D3 and trying to go through some of the examples to get a better understanding of how it works). I'm trying to modify one of the base examples for D3 (http://bl.ocks.org/mbostock/1667367). I've basically kept everything the same... I'm just trying to use a different csv file with my own data (vs. the S&P 500 stock data). In the example file, the csv file has a date (month year) and a stock price. In my data, I have a UTC time stamp and a light value (between 0-1000). Here's a small example of the csv:

date, light
2013-01-01T09:00:00.000Z,554.22
2013-01-01T09:01:00.000Z,480.83
2013-01-01T09:02:00.000Z,433.19
2013-01-01T09:03:00.000Z,596.89
2013-01-01T09:04:00.000Z,421.78
2013-01-01T09:05:00.000Z,461.23
2013-01-01T09:06:00.000Z,560.04

When, I run my code I get an error in the console window saying I have a parsing error (not sure if it's getting caught up in parsing the data or the light value)... Does anyone see a problem with how I'm setting up the csv file (or how I might be parsing it incorrectly)? Here's the D3 code I'm working with.

<!DOCTYPE html>
<meta charset="utf-8">
<style>

svg {
  font: 10px sans-serif;
}

path {
  fill: steelblue;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.brush .extent {
  stroke: #fff;
  fill-opacity: .125;
  shape-rendering: crispEdges;
}

</style>
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>

var margin = {top: 10, right: 10, bottom: 100, left: 40},
    margin2 = {top: 430, right: 10, bottom: 20, left: 40},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom,
    height2 = 500 - margin2.top - margin2.bottom;

var parseDate = d3.time.format("%Y-%m-%dT%H:%M:%S.%LZ").parse;

var x = d3.time.scale().range([0, width]),
    x2 = d3.time.scale().range([0, width]),
    y = d3.scale.linear().range([height, 0]),
    y2 = d3.scale.linear().range([height2, 0]);

var xAxis = d3.svg.axis().scale(x).orient("bottom"),
    xAxis2 = d3.svg.axis().scale(x2).orient("bottom"),
    yAxis = d3.svg.axis().scale(y).orient("left");

var brush = d3.svg.brush()
    .x(x2)
    .on("brush", brush);

var area = d3.svg.area()
    .interpolate("monotone")
    .x(function(d) { return x(d.date); })
    .y0(height)
    .y1(function(d) { return y(d.light); });

var area2 = d3.svg.area()
    .interpolate("monotone")
    .x(function(d) { return x2(d.date); })
    .y0(height2)
    .y1(function(d) { return y2(d.light); });

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

svg.append("defs").append("clipPath")
    .attr("id", "clip")
    .append("rect")
    .attr("width", width)
    .attr("height", height);

var focus = svg.append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

var context = svg.append("g")
    .attr("transform", "translate(" + margin2.left + "," + margin2.top + ")");

d3.csv("Light.csv", function(error, data) {
  console.log(data);

  data.forEach(function(d) {
    d.date = parseDate(d.date);
    //d.light = +d.light;
    //console.log(d);
  });

  x.domain(d3.extent(data.map(function(d) { return d.date; })));
  y.domain([0, d3.max(data.map(function(d) { return d.light; }))]);
  x2.domain(x.domain());
  y2.domain(y.domain());

  focus.append("path")
      .datum(data)
      .attr("clip-path", "url(#clip)")
      .attr("d", area);

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

  focus.append("g")
      .attr("class", "y axis")
      .call(yAxis);

  context.append("path")
      .datum(data)
      .attr("d", area2);

  context.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height2 + ")")
      .call(xAxis2);

  context.append("g")
      .attr("class", "x brush")
      .call(brush)
    .selectAll("rect")
      .attr("y", -6)
      .attr("height", height2 + 7);
});

function brush() {
  x.domain(brush.empty() ? x2.domain() : brush.extent());
  focus.select("path").attr("d", area);
  focus.select(".x.axis").call(xAxis);
}

</script>

Upvotes: 0

Views: 3658

Answers (2)

Digikata
Digikata

Reputation: 1959

In the header of your csv file, the "light" header has an extra space in front of it. That leads to processing problems with d3.csv.

data.forEach(function(d) {
  d.date = parseDate(d.date);
  d.light = +d.light;  // won't be able to access the light column data with the space
  d.light = d[' light']; // this would work if you can't fix the header at the csv source
});

Hmmm, maybe I'll submit a patch to d3 to fix this...

Upvotes: 1

Lars Kotthoff
Lars Kotthoff

Reputation: 109232

You are probably getting that error because of your time format specification -- there is no %L placeholder (see the documentation). This should work.

var parseDate = d3.time.format("%Y-%m-%dT%H:%M:%S.000Z").parse;

Upvotes: 0

Related Questions