markdown freeCodeCamp：使用条形图可视化数据

Posted 2021-05-06

body {
  background-color: #ddd;
  background-repeat: repeat;
  background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAFAAAACgCAMAAACsXRuGAAAADFBMVEWIiIjd3d3y8vLm5uZzdc63AAAAbklEQVR42u3ZIQ4AIAwDwI39/8/wAlTFxFUgm5ALmFZV51Iv52Vyx/7CzhdONr3/ylCgQIECBQoUKFCgQIECBQoUKFCgQIECBcrmccGe4qX4vqBAgQIFChQoUKBAgQIFChQoUKBAgQIFij3lX3gBXBBzc8FaGvIAAAAASUVORK5CYII=)
}

.chart {
  margin: 0px auto;
  padding: 0px;
  background-color: white;
}

.notes {
  font-size: 12px;
  font-family: sans-serif;
  color: steelblue;
  padding: 20px;
  text-align: center;
}

.title {
  font-size: 2.5em;
  font-family: sans-serif;
  color: steelblue;
  text-align: center;
  padding: 15px 0px 5px 0px;
}

p {
  margin: 0;
}

.chart .mouseover {
  fill: lightsteelblue;
}

.chart rect,
.chart .mouseoff {
  fill: steelblue;
}

.chart text {
  fill: black;
  font: 10px sans-serif;
  text-anchor: end;
}

.axis text {
  font: 15px sans-serif;
}

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

.card {
  background-color: white;
  margin: 40px auto;
  padding: 0px;
  width: 1050px;
  height: 640px;
  box-shadow: 0 3px 6px 0 rgba(0, 0, 0, 0.32), 0 3px 12px 0 rgba(0, 0, 0, 0.24);
}

.tooltip {
  position: absolute;
  text-align: left;
  width: auto;
  height: auto;
  padding: 3px 5px 3px 5px;
  font: 1em sans-serif;
  border: 0px;
  border-radius: 5px;
  pointer-events: none;
  box-shadow: 3px 3px 6px rgba(0, 0, 0, 0.2);
  background-color: lightsteelblue;
}

.amount {
  font-size: 1em;
  font-weight: bold;
}

.year {
  font-size: 0.8em;
  font-weight: normal;
}

<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/d3/3.5.3/d3.min.js"></script>

$('document').ready(function() {

  var url = 'https://raw.githubusercontent.com/FreeCodeCamp/ProjectReferenceData/master/GDP-data.json';

  var months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];

  var formatCurrency = d3.format("$,.2f");

  $.getJSON(url).success(function(jsonData) {
    var data = jsonData.data;

    console.log(data);
    console.log(JSON.stringify(jsonData));

    d3.select(".notes")
      .append("text")
      .text(jsonData.description);

    var margin = {
        top: 5,
        right: 10,
        bottom: 30,
        left: 75
      },
      width = 1000 - margin.left - margin.right,
      height = 500 - margin.top - margin.bottom;

    var barWidth = Math.ceil(width / data.length);

    minDate = new Date(data[0][0]);
    maxDate = new Date(data[274][0]);

    var x = d3.time.scale()
      .domain([minDate, maxDate])
      .range([0, width]);

    var y = d3.scale.linear()
      .range([height, 0])
      .domain([0, d3.max(data, function(d) {
        return d[1];
      })]);

    var xAxis = d3.svg.axis()
      .scale(x)
      .orient("bottom")
      .ticks(d3.time.years, 5);

    var yAxis = d3.svg.axis()
      .scale(y)
      .orient("left")
      .ticks(10, "");

    var infobox = d3.select(".infobox");

    var div = d3.select(".card").append("div")
      .attr("class", "tooltip")
      .style("opacity", 0);

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

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

    chart.append("g")
      .attr("class", "y axis")
      .call(yAxis)
      .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", "0.8em")
      .style("text-anchor", "end")
      .text("Gross Domestic Product, USA");

    chart.selectAll(".bar")
      .data(data)
      .enter().append("rect")
      .attr("class", "bar")
      .attr("x", function(d) {
        return x(new Date(d[0]));
      })
      .attr("y", function(d) {
        return y(d[1]);
      })
      .attr("height", function(d) {
        return height - y(d[1]);
      })
      .attr("width", barWidth)
      .on("mouseover", function(d) {
        var rect = d3.select(this);
        rect.attr("class", "mouseover");
        var currentDateTime = new Date(d[0]);
        var year = currentDateTime.getFullYear();
        var month = currentDateTime.getMonth();
        var dollars = d[1];
        div.transition()
          .duration(200)
          .style("opacity", 0.9);
        div.html("<span class='amount'>" + formatCurrency(dollars) + "&nbsp;Billion </span><br><span class='year'>" + year + ' - ' + months[month] + "</span>")
          .style("left", (d3.event.pageX + 5) + "px")
          .style("top", (d3.event.pageY - 50) + "px");
      })
      .on("mouseout", function() {
        var rect = d3.select(this);
        rect.attr("class", "mouseoff");
        div.transition()
          .duration(500)
          .style("opacity", 0);
      });

  });

});

<html lang="en">

<head>
  <meta charset="utf-8">

  <head>
    <title>D3-Zipline: GDP Bar Graph</title>
  </head>

  <body>
    <div class="card">
      <div class="title">Gross Domestic Product</div>
      <svg class="chart"></svg>
      <div class="notes"></div>
    </div>
  </body>

</html>

freeCodeCamp : Visualize Data with a Bar Chart
----------------------------------------------
Bar Chart:  
http://bost.ocks.org/mike/bar/3/

Data: 
//https://www.quandl.com/help/api

Mouseover effects: 
https://gist.github.com/sfrdmn





Forked from [Suzanne Atkinson](http://codepen.io/AdventureBear/)'s Pen [D3 GDP Visualization w/ Mouseovers](http://codepen.io/AdventureBear/pen/XbmNjG/).

Forked from [Bruce Young](http://codepen.io/MutantSpore/)'s Pen [D3 GDP Visualization w/ Mouseovers](http://codepen.io/MutantSpore/pen/pgyrwB/).

Forked from [Free Code Camp](http://codepen.io/FreeCodeCamp/)'s Pen [D3 GDP Visualization w/ Mouseovers](http://codepen.io/FreeCodeCamp/pen/adBBWd/).

A [Pen](https://codepen.io/harunpehlivan/pen/ddxWWe) by [HARUN PEHLİVAN](https://codepen.io/harunpehlivan) on [CodePen](https://codepen.io).

[License](https://codepen.io/harunpehlivan/pen/ddxWWe/license).