使用 D3 创建世界等值线地图答案

【问题标题】：Creating world choropleth map with D3使用 D3 创建世界等值线地图
【发布时间】：2016-11-15 04:43:47
【问题描述】：

我是一个新的 D3 用户，上周一直在绞尽脑汁想弄清楚如何创建一个基本的世界等值线地图并让它实际运行！我一直在尝试所有可用的代码和教程，但似乎没有任何效果！我试图显示的数据也包含在我的 json 中，作为“物种”。最后，我想要一个基本的等值线，它显示物种数据，当我将鼠标悬停在它上面时，它只提供国家名称和值。非常感谢任何建议或指导。

当前使用的代码（根据我的信息进行了编辑）（原始代码位于 http://bl.ocks.org/mbostock/3306362）

var width = 960,
    height = 500;

var color = d3.scale.threshold()
    .domain([0.02, 0.04, 0.06, 0.08, 0.10])
    .range(["#f2f0f7", "#dadaeb", "#bcbddc", "#9e9ac8", "#756bb1", "#54278f"]);

var path = d3.geo.path();

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

queue()
    .defer(d3.json, "World.geojson")
    .defer(d3.csv, "species.csv")
    .await(ready);

function ready(error, world, species) {
  if (error) throw error;

  var rateById = {};

  species.forEach(function(d) { rateById[d.ISO_3DIGIT] = +d.Species; });

  svg.append("g")
      .attr("class", "countries")
    .selectAll("path")
      .data(topojson.feature(world, world.objects.countries).features)
    .enter().append("path")
      .attr("d", path)
      .style("fill", function(d) { return color(rateById[d.ISO_3DIGIT]); });

  svg.append("path")
      .datum(topojson.mesh(world, world.objects.countries, function(a, b) { return a.ISO_3DIGIT !== b.ISO_3DIGIT; }))
      .attr("class", "countries")
      .attr("d", path);
}

我的 json 示例

    {
"type": "FeatureCollection",
"crs": { "type": "name", "properties": { "name":      "urn:ogc:def:crs:OGC:1.3:CRS84" } },

"features": [
{ "type": "Feature", "properties": { "OBJECTID": 3, "FIPS_CNTRY": "AA",     "ISO_3DIGIT": "ABW", "NAME": "Aruba", "LONG_NAME": "Aruba", "Shape_Leng":    0.698924, "Shape_Area": 0.015129, "Number_of_": 26.000000, "Species": "26" },    "geometry": { "type": "MultiPolygon", "coordinates": [ [ [ [ -69.991201758254533, 12.564936161074968 ], [ -69.987234354082148, 12.559555769083488 ], [ -69.983659267461235, 12.557785153262216 ], [ -69.977896332649607, 12.558793663796507 ], [ -69.979292630850239, 12.557989954972413 ], [ -69.978672147201848, 12.556384921426968 ], [ -69.97182917607563, 12.552132010383957 ], [ -69.971315503107974, 12.549742102516007 ], [ -69.969411254325905, 12.550420641899109 ], [ -69.963384270467714, 12.546648621736495 ], [ -69.962705135733415, 12.546379327843681 ], [ -69.960937500265402, 12.54659593135716 ], [ -69.958110928376641, 12.546536564410928 ], [ -69.957436323527475, 12.545586347931589 ], [ -69.956397414109347, 12.543688773917779 ], [ -69.955672860014488, 12.537055253996755 ], [ -69.94667124708036, 12.540498614219644 ], [ -69.944165825792197, 12.536637425376853 ], [ -69.940813541711577, 12.53483021254425 ], [ -69.933964252848, 12.527834058095266 ], [ -69.928611516808019, 12.525171756371435 ], [ -69.928868055616249, 12.521762966987296 ], [ -69.926651835613711, 12.517770409676643 ], [ -69.926916956652235, 12.515210151327381 ], [ -69.924417734390943, 12.515246749238088 ], [ -69.924206257013111, 12.513279556906014 ], [ -69.918271422188354, 12.508972763881957 ], [ -69.917961121008943, 12.506630659477366 ], [ -69.909244775725824, 12.502312660001223 ], [ -69.898086666766233, 12.489711761488593 ], [ -69.895915150263988, 12.485523343527461 ], [ -69.890029430114112, 12.485061645078815 ], [ -69.887601852343607, 12.482514620253482 ], [ -69.886337637571899, 12.480468749832937 ], [ -69.886398077409353, 12.480468749832937 ], [ -69.884469747480864, 12.478347062966577 ], [ -69.883330345119305, 12.475240111242101 ], [ -69.881198167661296, 12.463264107552504 ], [ -69.87345480879236, 12.447664141786674 ], [ -69.873569250220726, 12.43877196285581 ], [ -69.871752858007994, 12.436580657671186 ], [ -69.868788957844117, 12.423137068321012 ], [ -69.865280151257934, 12.41843080543731 ], [ -69.866732954762028, 12.415024757186757 ], [ -69.870972514469941, 12.414948224880675 ], [ -69.873276234010973, 12.412573218779016 ], [ -69.88098335289942, 12.41400110746514 ], [ -69.88356542610353, 12.413048505983738 ], [ -69.884616732676079, 12.414072513635574 ], [ -69.884146571607005, 12.417217254872412 ], [ -69.887623310167612, 12.420512437399054 ], [ -69.890819430572265, 12.421990751971634 ], [ -69.895043253943015, 12.42066562162114 ], [ -69.904002309159239, 12.426742315505464 ], [ -69.905593753049232, 12.426611900318903 ], [ -69.908368229909854, 12.430709243037143 ], [ -69.911455273342199, 12.430269956593236 ], [ -69.912853240684512, 12.431570410446056 ], [ -69.91991043122141, 12.431113004461565 ], [ -69.92511200921183, 12.433772921183333 ], [ -69.9261195655655, 12.432376146342051 ], [ -69.927280545360873, 12.432524561459331 ], [ -69.927960872596202, 12.433737158742872 ], [ -69.927171945928535, 12.435858845609232 ], [ -69.924864053533213, 12.436950207086397 ], [ -69.925641417617328, 12.439117670344217 ], [ -69.932209610784923, 12.441419124492995 ], [ -69.931949854202401, 12.440304756559271 ], [ -69.932809710399795, 12.440086125973949 ], [ -69.940516829288242, 12.441873311803874 ], [ -69.941695213663195, 12.444035648926047 ], [ -69.944575071282486, 12.443960070800586 ], [ -69.949141621788385, 12.447995424149497 ], [ -69.953771352366005, 12.450386046978451 ], [ -69.957332611011168, 12.454207063105457 ], [ -69.960015535088871, 12.455209255003126 ], [ -69.960937500265402, 12.457031249992156 ], [ -69.965335846072435, 12.46140086695641 ], [ -69.968737721468642, 12.463189721028812 ], [ -69.970178961489864, 12.465870976864096 ], [ -69.971952557664395, 12.465869546042711 ], [ -69.975418925243218, 12.468608975423876 ], [ -69.974787950103803, 12.474527478560276 ], [ -69.975870370521193, 12.473966240449613 ], [ -69.976553559399235, 12.469965219619155 ], [ -69.977643847085858, 12.469150305242351 ], [ -69.978891372239048, 12.470363021236437 ], [ -69.977841854418045, 12.47226095228109 ], [ -69.990635752837704, 12.478773474716093 ], [ -69.989674448616881, 12.47935545479038 ], [ -69.990520358128038, 12.480256677103966 ], [ -69.99439775904932, 12.481073141012644 ], [ -69.995885371712518, 12.478585839265065 ], [ -69.998836756011485, 12.480469346083453 ], [ -70.000186443249731, 12.480844259055289 ], [ -70.000915646839644, 12.484424948452613 ], [ -70.010489702537711, 12.488595008552807 ], [ -70.012077451113441, 12.49105381977796 ], [ -70.009847760165997, 12.490551233652525 ], [ -70.009806275339315, 12.492042660340474 ], [ -70.017953276922185, 12.499185323343966 ], [ -70.020050763931579, 12.499186754165351 ], [ -70.020542144504361, 12.499400615645868 ], [ -70.028274059500234, 12.503120660390152 ], [ -70.029504418394197, 12.50432467454408 ], [ -70.030076026587324, 12.50544083122935 ], [ -70.030136943065486, 12.509627223017901 ], [ -70.033386826740639, 12.514538526831529 ], [ -70.036986828179579, 12.514753103273108 ], [ -70.042536974401855, 12.518800258425188 ], [ -70.043136954406918, 12.520274519753286 ], [ -70.046085357453251, 12.521554708283134 ], [ -70.050869106823825, 12.525797605375146 ], [ -70.053049444776036, 12.530033350158988 ], [ -70.056365132744645, 12.530872344782892 ], [ -70.058509111106559, 12.536482572912405 ], [ -70.063081979349874, 12.539495944782004 ], [ -70.062934040873301, 12.541902780588828 ], [ -70.062373756943316, 12.543691158020522 ], [ -70.055176973638424, 12.554270028938674 ], [ -70.055221438818307, 12.560495853800603 ], [ -70.047874331135461, 12.568862318741026 ], [ -70.045472264433442, 12.575522660942056 ], [ -70.04475784300007, 12.580821037460908 ], [ -70.04475784300007, 12.581284642472269 ], [ -70.046714544740439, 12.588581204658851 ], [ -70.050084113790831, 12.595303773650244 ], [ -70.053751349445236, 12.610625743683102 ], [ -70.058658242084221, 12.616226554112188 ], [ -70.057161450040894, 12.622090339797353 ], [ -70.052592754651869, 12.623774051431326 ], [ -70.051294803612279, 12.623705506004285 ], [ -70.049635767576603, 12.621721744562819 ], [ -70.046384453979329, 12.620525240647339 ], [ -70.041723132016898, 12.613908410344834 ], [ -70.033449649781517, 12.609635948939854 ], [ -70.03106045687457, 12.606407165158544 ], [ -70.023722171540953, 12.603497504905931 ], [ -70.017495036366824, 12.595313549280888 ], [ -70.013124227800859, 12.586606860018549 ], [ -69.99986994304345, 12.572924852300105 ], [ -69.993902921482629, 12.568243979975705 ], [ -69.991201758254533, 12.564936161074968 ] ] ] ] } },
{ "type": "Feature", "properties": { "OBJECTID": 4, "FIPS_CNTRY": "AC", "ISO_3DIGIT": "ATG", "NAME": "Antigua and Barbuda", "LONG_NAME": "Antigua and Barbuda", "Shape_Leng": 2.893306, "Shape_Area": 0.037020, "Number_of_": 32.000000, "Species": "32" }, "geometry": { "type": "MultiPolygon", "coordinates": [ [ [ [ -62.34320020652433, 16.932690858

如果有用的话，这里是我的 cvs 的 sn-p：

OBJECTID,ISO_3DIGIT,NAME,LONG_NAME,Species
3,ABW,Aruba,Aruba,26
4,ATG,Antigua and Barbuda,Antigua and Barbuda,32
5,ARE,United Arab Emirates,United Arab Emirates,37
6,AFG,Afghanistan,Islamic Republic of Afghanistan,33
7,DZA,Algeria,People's Democratic Republic of Algeria,68
8,AZE,Azerbaijan,Republic of Azerbaijan,38
9,ALB,Albania,Republic of Albania,57
10,ARM,Armenia,Republic of Armenia,27

任何关于我做错了什么的建议将不胜感激。感觉到最后我都没有头发了哈哈。

【问题讨论】：

到目前为止你有什么？控制台中的任何错误？地图是没有颜色显示，还是根本不显示？如果你 console.log "world" 和 "species" 会发生什么？您提供的信息越多越好。
@GerardoFurtado 到目前为止什么都没有！我收到一条错误消息，提示“未定义不是对象（评估'world.objects.countries'）”当我输入“世界”时，我得到= $1，然后是“物种”= $2
将console.log(world)作为“准备”函数的第一行，与物种相同，并告诉我结果。
同样的错误... :( TypeError: undefined is not an object (evaluating 'world.objects.countries')
[plnkr.co/edit/mbn8E5RDZdep174fDKEH?p=info] 喜欢吗？

标签： javascript json d3.js choropleth

【解决方案1】：

首先，您需要decide if you want to use geojson 或topojson 来构建您的地图。看起来您的地图数据在 geojson 中，但您正在尝试使用 topojson 构造来构建它。

其次，您没有为您的地图提供投影来控制它的display。

第三，您的色阶似乎与您的数据不匹配。这些值以 10 为单位，而您的比例仅以百分之一定义。

应用这些修复程序开始制作地图。 See example here。

注意，我必须找到自己的 GEOJson，所以它可能与您的格式不完全匹配。

【讨论】：