我正在尝试使用来自ABS的数据和json地理数据制作热图。出于某种原因，当我对此进行测试时，它只为所有段分配一种颜色，而不是为较高/较低的数字分配较浅/较深的颜色。我相信我的代码正在为 json 中的每个地图段分配一个值，但由于某种原因，色阶未应用于这些值。
这是我的 d3 代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>D3: Setting path fills dynamically to generate a choropleth</title>
<script type="text/javascript" src="d3.js"></script>
<style type="text/css">
/* No style rules here yet */
</style>
</head>
<body>
<script type="text/javascript">
//Width and height
var w = 1000;
var h = 600;
var path = d3.geoPath()
.projection(d3.geoMercator()
.center([151,-33.5])
.scale(17000)
.translate([w/2,h/2]));
//Define quantize scale to sort data values into buckets of color
var color = d3.scaleQuantize()
.range(["rgb(237,248,233)","rgb(186,228,179)","rgb(116,196,118)","rgb(49,163,84)","rgb(0,109,44)"]);
//Colors derived from ColorBrewer, by Cynthia Brewer, and included in
//https://github.com/d3/d3-scale-chromatic
//Create SVG element
var svg = d3.select("body")
.append("svg")
.attr("width", w)
.attr("height", h);
//Load in agriculture data
d3.csv("ManagerArea.csv", function(data) {
//Set input domain for color scale
color.domain([
d3.min(data, function(d) { return d.value; }),
d3.max(data, function(d) { return d.value; })
]);
//Load in GeoJSON data
d3.json("australia_adm2.json", function(json) {
//Merge the ag. data and GeoJSON
//Loop through once for each ag. data value
for (var i = 0; i < data.length; i++) {
//Grab state name
var dataState = data[i].state;
//Grab data value, and convert from string to float
var dataValue = parseFloat(data[i].value);
//Find the corresponding state inside the GeoJSON
for (var j = 0; j < json.features.length; j++) {
var jsonState = json.features[j].properties.sa4_name11;
if (dataState == jsonState) {
//Copy the data value into the JSON
json.features[j].properties.value = dataValue;
//Stop looking through the JSON
break;
}
}
}
//Bind data and create one path per GeoJSON feature
svg.selectAll("path")
.data(json.features)
.enter()
.append("path")
.attr("d", path)
.style("fill", function(d) {
//Get data value
var value = d.properties.value;
if (value) {
//If value exists…
return color(value);
} else {
//If value is undefined…
return "#ccc";
}
});
});
});
</script>
</body>
</html>
我的 json 地理数据中的命名：
{"type"："FeatureCollection"， "Features"： [ {"类型"："要素"，"几何"：{"类型"："多多边形"，"坐标"：...
..."properties"：{"cartodb_id"：1，"sa4_name11"："悉尼 - 包尔克汉姆山和霍克斯伯里"，"right_dpop"：38742，"right_opop"：69540，"right_xcoord"：150.8288053，"right_ycoord"：-33.36860558}}，
我的 csv 数据：
state,value
Capital Region,15558
Central Coast,15642
Central West,13074
Coffs Harbour - Grafton,6274
Far West and Orana,7968
Hunter Valley exc Newcastle,11717
Illawarra,13278
Mid North Coast,8758
Murray,8298
New England and North West,12884
Newcastle and Lake Macquarie,15980
Richmond - Tweed,12013
Riverina,11055
Southern Highlands and Shoalhaven,7191
Sydney - Baulkham Hills and Hawkesbury,19904
Sydney - Blacktown,14710
Sydney - City and Inner South,27758
Sydney - Eastern Suburbs,24778
Sydney - Inner South West,27081
Sydney - Inner West,24055
Sydney - North Sydney and Hornsby,39796
Sydney - Northern Beaches,24080
Sydney - Outer South West,12403
Sydney - Outer West and Blue Mountains,15767
Sydney - Parramatta,20323
Sydney - Ryde,13468
Sydney - South West,15090
Sydney - Sutherland,16901
结果
我认为问题出在本节中：
color.domain([
d3.min(data, function(d) { return d.value; }),
d3.max(data, function(d) { return d.value; })
]);
d.value被视为字符串而不是数字。它应该是一个数字。你可以通过使用这篇文章中提到的parseFloat(d.value)或插入一元加号来使其成为一个数字：+d.value，如Mike Bostock的合唱