We Keep Coding

D3 skipping first two features in a TopoJson

I am creating an interactive visualization tool with D3. I just got my map working today and I noticed that the first two features from the topojson are not loading in.
The first two entries of the topojson look like this and geojson.io reads these countries in fine. (They appear on the map)
"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]]],
Here is my 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
};
I believe the issue is with the map.selectAll("path") chunk. When I run it without D3 iterating through features it seems to come out fine. (With Indonesia and Malaysia still there. )

The issue is here:
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)
The two append statements create paths, you then select these existing paths when you do: map.selectAll("path"). To confirm, before you append the features, you can do console.log(map.selectAll("path").size()) to see how many elements are selected, it should be two.
An enter selection can be used to create elements in the DOM for each item in the data array that does not have a corresponding element in the DOM.
As there are two paths in your selection, the first two items in the data array correspond to these two elements, and thus do not need to be entered: they already exist (By binding the data with .data() you are binding the first two datums in the data array to the already existing paths). D3 doesn't "know" that these paths aren't supposed to be affiliated with those data array items.
In order to ensure all items are entered you can make sure that you have an empty selection before you bind data:
map.selectAll(null).data()...
map.selectAll().data()...
map.selectAll(".className").data()... // where no element has that class yet

Creating a rectangle chart with D3.js

I am trying to make a d3 javascript that creates a rectangle whose color depends on a data set. All of the rectangles are adjacent to each other like:
[][][][][][]
[][][][][][]
I got my script to work to create rectangles for all of my data, but it overflows like:
[][][][][][][][][][][][][][][][][][][][][][][][][][][]
How can I create width and height properties for my d3 script so it looks more like
[][][][]
[][][][]
[][][][]
Here is my script:
<script>
//for whatever data set
var data = [];
//Make an SVG Container
var svgContainer = d3.select("body").selectAll("svg")
.data(data)
.enter().append("svg")
.attr("width", 38)
.attr("height", 25);
//Draw the rectangle
var rectangle = svgContainer.append("rect")
.attr("x", 0)
.attr("y", 5)
.attr("width", 38)
.attr("height", 25);
</script>

You have to change the x and y properties.
.attr("x", function(d, i) {
return 5 + (i%itemPerLine) * widthRect;
})
.attr("y", function(d, i) {
return 5 + Math.floor(i/itemPerLine) * heightRect;
})
(itemPerLine is the number of rect per line)
See this fiddle as example

D3 Map - Cannot apply the suitable projection for indian map

I am trying to draw the states of India map (with disputed territories ) by D3 Map. I successfully generate the topojson file which looks good in http://www.mapshaper.org/
And the json link is https://dl.dropboxusercontent.com/s/wk9qd47wn1nhsjm/dddtopo.json
But I failed to draw the map. The link http://jsfiddle.net/sEFjd/47/ is how I did under jsfiddle.
var topoJsonUrl = "https://dl.dropboxusercontent.com/s/wk9qd47wn1nhsjm/dddtopo.json";
var width = 360,
height = 360;
d3.json(topoJsonUrl, function(error, mx) {
var projection = d3.geo.mercator();
// create the path
var path = d3.geo.path().projection(projection);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
console.log(mx);
var geoPaths = svg.append("g")
.attr("class", "municipalities")
.selectAll("path")
.data(topojson.feature(mx, mx.objects.india).features);
geoPaths.enter().append("path")
.attr("d", path);
var p= svg.append("path")
.datum(topojson.mesh(mx, mx.objects.india))
.attr("d", path)
.attr("class", "state-boundary");
geoPaths.style("fill", function(d) {
return Math.random() > 0.5 ?'gray' : 'blue';
});
});
The code works well with other countries(Germany, Mexico) Not sure why it does not work this time. Any help will be very appreciated.

Drawing states separately with d3 js and country topojson file

I have a topojson which contains state's paths. I want the user to be able to hover over a state and the state to appear in a different svg. So far, I've tried to extract the geometry out of the topojson (d.geometry , d.geometry.coordinates etc) But I'm not able to do it.
Maybe I need to draw a polygon out of that, but some states are of type "Polygon" and some of them are of type "MultiPolgyon".
Any ideas/suggestions?
Edit : Here's my code
var svg = d3.select("#india-map")
.append("svg")
.attr("width",width).attr("preserveAspectRatio", "xMidYMid")
.attr("viewBox", "0 0 " + width + " " + height)
.attr("height", height)
var stateSvg = d3.select("#state-map")
.append("svg")
.append("g")
.attr("height", height)
.attr("width", width);
var g = svg.append("g");
var projection = d3.geo.mercator()
.center([86, 27])
.scale(1200);
var path = d3.geo.path().projection(projection);
var pc_geojson = topojson.feature(pc, pc.objects.india_pc_2014);
var st_geojson = topojson.feature(state_json, state_json.objects.india_state_2014);
g.selectAll(".pc")
.data(pc_geojson.features)
.enter().append("path")
.attr("class", "pc")
.attr("d", path)
.attr("id", function(d){ return d.properties.Constituency;})
.attr("fill", "orange")
.on("click", function(d){
drawCons(d);
});
function drawCons(d){
stateSvg.selectAll(".pc2")
.data(d)
.enter().append("path")
.attr("class","pc2")
.attr("d", path)
}

.data() expects to be given an array of objects to be matched against the selection. You're passing a single object, so it doesn't work. You can either use .datum(d) or .data([d]) to make it work.
Quick and dirty demo here.

plots on multiple instances of graph

I'm using the d3 library to plot a bar graph with JSON objects recieved from the server through websockets. What is happening though is that each time the graph is plotted it draws a new instance of a graph. So I end up with multiple graphs.
But I want the JSON data to be all plotted onto the same one graph.
Here's my code:
ws = new WebSocket("ws://localhost:8888/dh");
var useData = []
//var chart;
var chart = d3.select("body")
.append("svg:svg")
.attr("class", "chart")
.attr("width", 420)
.attr("height", 200);
ws.onmessage = function(evt)
{
var distances = JSON.parse(evt.data);
data = distances.miles;
console.log(data);
if(useData.length <= 10){
useData.push(data)
}
else
{
var draw = function(data){
// Set the width relative to max data value
var x = d3.scale.linear()
.domain([0, d3.max(useData)])
.range([0, 420]);
var y = d3.scale.ordinal()
.domain(useData)
.rangeBands([0, 120]);
var rect = chart.selectAll("rect")
.data(useData)
// enter rect
rect.enter().append("svg:rect")
.attr("y", y)
.attr("width", x)
.attr("height", y.rangeBand());
// update rect
rect
.attr("y", y)
.attr("width", x)
.attr("height", y.rangeBand());
var text = chart.selectAll("text")
.data(useData)
// enter text
text.enter().append("svg:text")
.attr("x", x)
.attr("y", function (d) { return y(d) + y.rangeBand() / 2; })
.attr("dx", -3) // padding-right
.attr("dy", ".35em") // vertical-align: middle
.attr("text-anchor", "end") // text-align: right
.text(String);
// update text
text
.data(useData)
.attr("x", x)
.text(String);
}
useData.length = 0;
}
}
How can I plot all points onto on graph which is being constantly updated?
It's a shame that d3 cannot handle data in real-time and update charts accordingly, or if it can that there's no clear tutorial/ explanation of how to.
Thanks

My guess is because you're creating a chart every time with:
var chart = d3.select("body")
.append("svg:svg")
.attr("class", "chart")
.attr("width", 420)
.attr("height", 20 * useData.length);
Rather you need to check if chart exists, and if so, don't call that line.
// outside of .onmessage
var chart;
// inside of .onmessage
if (!chart) {
chart = d3.select("body")
.append("svg:svg")
.attr("class", "chart")
.attr("width", 420)
.attr("height", 20 * useData.length);
}

Like Brian said you keep creating a new svg element at every onmessage event. However, in D3 you don't need to use an if statement to check for element existence; after you do a data join, the enter() selection will only contain the elements that did not exist yet:
// data join
var chart = d3.select("body").selectAll(".chart")
.data([useData]); // if you wanted multiple charts: .data([useData1, useDate2, useData3])
// enter
chart.enter().append("svg") // this will only execute if the .chart did not exist yet
.attr("class", "chart")
.attr("width", 420);
// update (both new and existing charts)
chart
.attr("height", function(d) { return 20 * d.length; });
The concepts of the data join, enter(), update(), and exit() selections are explained in the Thing with Joins article. See also the 3 General Update Pattern articles.
You have to use a similar approach when you update or add new rect elements in your chart. Assuming for the moment that useData contains all accumulated data (although the useData.length = 0 might mean that is not the case):
// data join
var rects = chart.selectAll("rect")
.data(function(d) { return d; }); // use the data bound to each chart
// enter
rects.enter().append("rect");
// update
rects
.attr("y", function(d) { return y(d.yValue); }) // not sure what your data structure looks like
.attr("width", function(d) { return x(d.xValue); })
.attr("height", y.rangeBand());
// exit
rects.exit().remove();
Some suggestions how to update a path with real time data are given in Path Transitions.