我正在使用D3创建一个交互式可视化工具。我今天才开始使用我的地图，我注意到topojson的前两个功能没有加载。
topojson的前两个条目如下所示，geojson.io可以很好地读取这些国家。 （它们出现在地图上）
"objects":{"ne_10m_admin_0_countries":{"type":"GeometryCollection","geometries":[{"arcs":[[[0,1]],[[2,3,4,5]],[[6,7]],[[8,9]],[[10]],[[11]],[[12]],[[13]],[[14]],[[15]],[[16]],[[17]],[[18]],[[19]],[[20]],[[21]],[[22]],[[23]],[[24]],[[25]],[[26]],[[27]],[[28]],[[29]],[[30]],[[31]],[[32]],[[33]],[[34]],[[35]],[[36]],[[37]],[[38]],[[39]],[[40]],[[41]],[[42]],[[43]],[[44]],[[45]],[[46]],[[47]],[[48]],[[49]],[[50]],[[51]],[[52]],[[53]],[[54]],[[55]],[[56]],[[57]],[[58]],[[59]],[[60]],[[61]],[[62]],[[63]],[[64]],[[65]],[[66]],[[67]],[[68]],[[69]],[[70]],[[71]],[[72]],[[73]],[[74]],[[75]],[[76]],[[77]],[[78]],[[79]],[[80]],[[81]],[[82]],[[83]],[[84]],[[85]],[[86]],[[87]],[[88]],[[89]],[[90]],[[91]],[[92]],[[93]],[[94]],[[95]],[[96]],[[97]],[[98]],[[99]],[[100]],[[101]],[[102]],[[103]],[[104]],[[105]],[[106]],[[107]],[[108]],[[109]],[[110]],[[111]],[[112]],[[113]],[[114]],[[115]],[[116]],[[117]],[[118]],[[119]],[[120]],[[121]],[[122]],[[123]],[[124]],[[125]],[[126]],[[127]],[[128]],[[129]],[[130]],[[131]]],"type":"MultiPolygon","properties":{"featurecla":"Admin-0 country","scalerank":5,"LABELRANK":2,"SOVEREIGNT":"Indonesia","SOV_A3":"IDN","ADM0_DIF":0,"LEVEL":2,"TYPE":"Sovereign country","ADMIN":"Indonesia","ADM0_A3":"IDN","GEOU_DIF":0,"GEOUNIT":"Indonesia","GU_A3":"IDN","SU_DIF":0,"SUBUNIT":"Indonesia","SU_A3":"IDN","BRK_DIFF":0,"NAME":"Indonesia","NAME_LONG":"Indonesia","BRK_A3":"IDN","BRK_NAME":"Indonesia","BRK_GROUP":"","ABBREV":"Indo.","POSTAL":"INDO","FORMAL_EN":"Republic of Indonesia","FORMAL_FR":"","NAME_CIAWF":"Indonesia","NOTE_ADM0":"","NOTE_BRK":"","NAME_SORT":"Indonesia","NAME_ALT":"","MAPCOLOR7":6,"MAPCOLOR8":6,"MAPCOLOR9":6,"MAPCOLOR13":11,"POP_EST":260580739,"POP_RANK":17,"GDP_MD_EST":3028000,"POP_YEAR":2017,"LASTCENSUS":2010,"GDP_YEAR":2016,"ECONOMY":"4. Emerging region: MIKT","INCOME_GRP":"4. Lower middle income","WIKIPEDIA":-99,"FIPS_10_":"ID","ISO_A2":"ID","ISO_A3":"IDN","ISO_A3_EH":"IDN","ISO_N3":"360","UN_A3":"360","WB_A2":"ID","WB_A3":"IDN","WOE_ID":23424846,"WOE_ID_EH":23424846,"WOE_NOTE":"Exact WOE match as country","ADM0_A3_IS":"IDN","ADM0_A3_US":"IDN","ADM0_A3_UN":-99,"ADM0_A3_WB":-99,"CONTINENT":"Asia","REGION_UN":"Asia","SUBREGION":"South-Eastern Asia","REGION_WB":"East Asia & Pacific","NAME_LEN":9,"LONG_LEN":9,"ABBREV_LEN":5,"TINY":-99,"HOMEPART":1,"MIN_ZOOM":0,"MIN_LABEL":1.7,"MAX_LABEL":6.7,"NE_ID":1159320845,"WIKIDATAID":"Q252","NAME_AR":"إندونيسيا","NAME_BN":"ইন্দোনেশিয়া","NAME_DE":"Indonesien","NAME_EN":"Indonesia","NAME_ES":"Indonesia","NAME_FR":"Indonésie","NAME_EL":"Ινδονησία","NAME_HI":"इंडोनेशिया","NAME_HU":"Indonézia","NAME_ID":"Indonesia","NAME_IT":"Indonesia","NAME_JA":"インドネシア","NAME_KO":"인도네시아","NAME_NL":"Indonesië","NAME_PL":"Indonezja","NAME_PT":"Indonésia","NAME_RU":"Индонезия","NAME_SV":"Indonesien","NAME_TR":"Endonezya","NAME_VI":"Indonesia","NAME_ZH":"印度尼西亚"}},{"arcs":[[[132,-1]],[[133,134]],[[135,-8,136,137,138,139]],[[140]],[[141]],[[142]],[[143]],[[144]],[[145]]],"type":"MultiPolygon","properties":{"featurecla":"Admin-0 country","scalerank":5,"LABELRANK":3,"SOVEREIGNT":"Malaysia","SOV_A3":"MYS","ADM0_DIF":0,"LEVEL":2,"TYPE":"Sovereign country","ADMIN":"Malaysia","ADM0_A3":"MYS","GEOU_DIF":0,"GEOUNIT":"Malaysia","GU_A3":"MYS","SU_DIF":0,"SUBUNIT":"Malaysia","SU_A3":"MYS","BRK_DIFF":0,"NAME":"Malaysia","NAME_LONG":"Malaysia","BRK_A3":"MYS","BRK_NAME":"Malaysia","BRK_GROUP":"","ABBREV":"Malay.","POSTAL":"MY","FORMAL_EN":"Malaysia","FORMAL_FR":"","NAME_CIAWF":"Malaysia","NOTE_ADM0":"","NOTE_BRK":"","NAME_SORT":"Malaysia","NAME_ALT":"","MAPCOLOR7":2,"MAPCOLOR8":4,"MAPCOLOR9":3,"MAPCOLOR13":6,"POP_EST":31381992,"POP_RANK":15,"GDP_MD_EST":863000,"POP_YEAR":2017,"LASTCENSUS":2010,"GDP_YEAR":2016,"ECONOMY":"6. Developing region","INCOME_GRP":"3. Upper middle income","WIKIPEDIA":-99,"FIPS_10_":"MY","ISO_A2":"MY","ISO_A3":"MYS","ISO_A3_EH":"MYS","ISO_N3":"458","UN_A3":"458","WB_A2":"MY","WB_A3":"MYS","WOE_ID":23424901,"WOE_ID_EH":23424901,"WOE_NOTE":"Exact WOE match as country","ADM0_A3_IS":"MYS","ADM0_A3_US":"MYS","ADM0_A3_UN":-99,"ADM0_A3_WB":-99,"CONTINENT":"Asia","REGION_UN":"Asia","SUBREGION":"South-Eastern Asia","REGION_WB":"East Asia & Pacific","NAME_LEN":8,"LONG_LEN":8,"ABBREV_LEN":6,"TINY":-99,"HOMEPART":1,"MIN_ZOOM":0,"MIN_LABEL":3,"MAX_LABEL":8,"NE_ID":1159321083,"WIKIDATAID":"Q833","NAME_AR":"ماليزيا","NAME_BN":"মালয়েশিয়া","NAME_DE":"Malaysia","NAME_EN":"Malaysia","NAME_ES":"Malasia","NAME_FR":"Malaisie","NAME_EL":"Μαλαισία","NAME_HI":"मलेशिया","NAME_HU":"Malajzia","NAME_ID":"Malaysia","NAME_IT":"Malesia","NAME_JA":"マレーシア","NAME_KO":"말레이시아","NAME_NL":"Maleisië","NAME_PL":"Malezja","NAME_PT":"Malásia","NAME_RU":"Малайзия","NAME_SV":"Malaysia","NAME_TR":"Malezya","NAME_VI":"Malaysia","NAME_ZH":"马来西亚"}},{"arcs":[[[146,147,148,149]],[[150,151,152,153]],[[154]],[[155]],[[156]],[[157]],[[158]],[[159]],[[160]],[[161]],[[162]],[[163]],[[164]],[[165]],[[166]],[[167]],[[168]],[[169]],[[170]],[[171]],[[172]],[[173]],[[174]],[[175]],[[176]],[[177]],[[178]],[[179]],[[180]],[[181]],[[182]],[[183]],[[184]],[[185]],[[186]],[[187]],[[188]],[[189]],[[190]],[[191]],[[192]],[[193]],[[194]],[[195]],[[196]],[[197]],[[198]],[[199]],[[200]],[[201]],[[202]],[[203]],[[204]],[[205]],[[206]],[[207]],[[208]],[[209]],[[210]],[[211]],[[212]],[[213]],[[214]],[[215]],[[216]],[[217]],[[218]],[[219]],[[220]],[[221]],[[222]],[[223]],[[224]],[[225]],[[226]],[[227]],[[228]],[[229]],[[230]],[[231]],[[232]],[[233]],[[234]],[[235]],[[236]],[[237]]],
这是我的JS：
<script>window.onload = setMap();
function setMap(){
d3.csv("/data/fdata.csv").then(function(data) {
//console.log(data);
d3.json("/data/a.topojson").then(function(data2) {
//console.log(data2);
var width = 960,
height = 460;
//create new svg container for the map
var map = d3.select("body")
.append("svg")
.attr("class", "map")
.attr("width", width)
.attr("height", height);
var projection = d3.geoNaturalEarth1()
.center([0, 0])
.rotate([-2, 0, 0])
//.parallels([43, 62])
.scale(175)
.translate([width / 2, height / 2]);
var path = d3.geoPath()
.projection(projection);
d3.selectAll(".boundary")
.style("stroke-width", 1 / 1);
var b = topojson.feature(data2, data2.objects.ne_10m_admin_0_countries);
var graticule = d3.geoGraticule();
var attrArray = ["x1","x2","x3" ];
function joinData(b, data){
for (var i=0; i<data.length; i++){
var csvRegion = data[i]; //the current region
var csvKey = data[i].Country; //the CSV primary key
for (var a=0; a<b.features.length; a++){
var geojsonProps = b.features[a].properties; //gj props
var geojsonKey = geojsonProps.ADMIN; //the geojson primary key
if (geojsonKey == csvKey){
attrArray.forEach(function(attr){
var val = parseFloat(csvRegion[attr]);
geojsonProps[attr] = val;
});
};
};
};
return b;
};
joinData(b,data);
var tooltip = d3.select("body").append("div")
.attr("class", "tooltip")
.style("opacity", 0);
var currentF = "B2";
var color = d3.scaleQuantile()
.domain(d3.range(0, 1000))
.range(d3.schemeReds[7]);
map.append("path")
.datum(graticule)
.attr("class", "graticule")
.attr("d", path);
map.append("path")
.datum(graticule.outline)
.attr("class", "graticule outline")
.attr("d", path);
map.selectAll("path")
.data(b.features)
.enter()
.append("path")
.attr("d", path)
//.style("stroke", "black")
.on("mouseover", function(d) {
tooltip.transition()
.duration(200)
.style("opacity", .9)
.style("stroke-opacity", 1.0);
tooltip.html(d.properties.ADMIN)
.style("left", (d3.event.pageX) + "px")
.style("top", (d3.event.pageY - 28) + "px");
})
.on("mouseout", function(d) {
tooltip.transition()
.duration(500)
.style("opacity", 0)
.style("stroke-opacity", 0);
})
.style("fill", function(d) { return color(d.properties[currentF]); });
}); //csv
}); //json
};
我认为问题在于map.selectAll("path")块。当我在不使用D3遍历功能的情况下运行它时，看起来效果很好。 （印尼和马来西亚仍然存在。）
答案 0 :(得分：0)
问题在这里：
map.append("path")
.datum(graticule)
.attr("class", "graticule")
.attr("d", path);
map.append("path")
.datum(graticule.outline)
.attr("class", "graticule outline")
.attr("d", path);
map.selectAll("path")
.data(b.features)
.enter()
.append("path")
.attr("d", path)
这两个append语句创建路径，然后在执行以下操作时选择这些现有路径：map.selectAll("path")。要确认，在附加功能之前，您可以执行console.log(map.selectAll("path").size())以查看选择了多少个元素，应该是两个。
回车选择可用于在DOM中为数据数组中在DOM中没有对应元素的每个项目创建元素。
由于您选择了两条路径，因此数据数组中的前两项对应于这两个元素，因此无需输入：它们已经存在（通过将数据与{{1 }}，您将数据数组中的前两个基准绑定到已经存在的路径）。 D3并不“知道”这些路径不应该与这些数据数组项相关联。
为了确保输入所有项目，可以在绑定数据之前确保选择为空：
.data()