Question

我试图使用来自ABS的数据和json地理数据制作热图。出于某种原因，当我测试它时，它只为所有段分配一种颜色，而不是为更高/更低的数字指定更亮/更暗的颜色。我相信我的代码是为json中的每个地图段分配一个值，但由于某种原因，颜色比例不适用于这些值。

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：

{＆＃34; type＆＃34;：＆＃34; FeatureCollection＆＃34;，＆＃34; features＆＃34;：[ {＆＃34;类型＆＃34;：＆＃34;特征＆＃34;＆＃34;几何＆＃34; {＆＃34;类型＆＃34;：＆＃34;的MultiPolygon＆＃34;＆＃34 ;坐标＆＃34;：...

...＆＃34;属性＆＃34;：{＆＃34; cartodb_id＆＃34;：1，＆＃34; sa4_name11＆＃34;：＆＃34;悉尼 - Baulkham Hills和Hawkesbury＆＃34;，＆＃34; right_dpop＆＃34;：38742＆＃34; right_opop＆＃34;：69540＆＃34; right_xcoord＆＃34;：150.8288053，＆＃34; right_ycoord＆＃34;： - 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

Result

Answer 1

我认为问题出在本节：

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。您可以使用on this post中的parseFloat(d.value)或插入Mike Bostock's choropleth中使用的一元加号+d.value来将其设为数字。

D3热图 - 仅显示一种颜色的色标

1 个答案: