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Migrating d3 v2 to d3 v4 for Chord Diagram

I am using this example to guide my foray into chord diagrams with d3. I have it working with my data in v2 (the version the example is in), and now I am attempting to upgrade to v4.
Here is the code that works with v2:
<script src="http://d3js.org/d3.v2.min.js?2.8.1"></script>
<script>
var width = 900,
height = 900,
outerRadius = Math.min(width, height) / 2 - 10,
innerRadius = outerRadius - 24;
var formatPercent = d3.format(",.0f");
var arc = d3.svg.arc()
.innerRadius(innerRadius)
.outerRadius(outerRadius);
var layout = d3.layout.chord()
.padding(.02)
.sortSubgroups(d3.descending)
.sortChords(d3.ascending);
var path = d3.svg.chord()
.radius(innerRadius);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("id", "circle")
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");
svg.append("circle")
.attr("r", outerRadius);
d3.csv("teams.csv", function(cities) {
d3.json("matrix.json", function(matrix) {
// Compute the chord layout.
layout.matrix(matrix);
// Add a group per neighborhood.
var group = svg.selectAll(".group")
.data(layout.groups)
.enter().append("g")
.attr("class", "group")
.on("mouseover", mouseover);
// Add a mouseover title.
group.append("title").text(function(d, i) {
return cities[i].name + ": " + formatPercent(d.value) + " as business unit";
});
// Add the group arc.
var groupPath = group.append("path")
.attr("id", function(d, i) { return "group" + i; })
.attr("d", arc)
.style("fill", function(d, i) { return cities[i].color; });
// Add the chords.
var chord = svg.selectAll(".chord")
.data(layout.chords)
.enter().append("path")
.attr("class", "chord")
.style("fill", function(d) { return cities[d.source.index].color; })
.attr("d", path);
// Add an elaborate mouseover title for each chord.
chord.append("title").text(function(d) {
return cities[d.source.index].name
+ " → " + cities[d.target.index].name
+ ": " + formatPercent(d.source.value)
+ "\n" + cities[d.target.index].name
+ " → " + cities[d.source.index].name
+ ": " + formatPercent(d.target.value);
});
function mouseover(d, i) {
chord.classed("fade", function(p) {
return p.source.index != i
&& p.target.index != i;
});
}
});
});
</script>
Here is the same code midway through my attempt to migrate to v4:
<script src="http://d3js.org/d3.v4.min.js"></script>
<script>
var width = 900,
height = 900,
outerRadius = Math.min(width, height) / 2 - 10,
innerRadius = outerRadius - 24;
var formatPercent = d3.format(",.0f");
var arc = d3.arc()
.innerRadius(innerRadius)
.outerRadius(outerRadius);
var layout = d3.chord()
.padAngle(.02)
.sortSubgroups(d3.descending)
.sortChords(d3.ascending);
var path = d3.ribbon()
.radius(innerRadius);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("id", "circle")
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");
svg.append("circle")
.attr("r", outerRadius);
d3.csv("teams.csv", function(cities) {
d3.json("matrix.json", function(matrix) {
// Compute the chord layout.
layout.matrix(matrix);
// Add a group per neighborhood.
var group = svg.selectAll(".group")
.data(layout.groups)
.enter().append("g")
.attr("class", "group")
.on("mouseover", mouseover);
// Add a mouseover title.
group.append("title").text(function(d, i) {
return cities[i].name + ": " + formatPercent(d.value) + " as business unit";
});
// Add the group arc.
var groupPath = group.append("path")
.attr("id", function(d, i) { return "group" + i; })
.attr("d", arc)
.style("fill", function(d, i) { return cities[i].color; });
// Add the chords.
var chord = svg.selectAll(".chord")
.data(layout.chords)
.enter().append("path")
.attr("class", "chord")
.style("fill", function(d) { return cities[d.source.index].color; })
.attr("d", path);
// Add an elaborate mouseover title for each chord.
chord.append("title").text(function(d) {
return cities[d.source.index].name
+ " → " + cities[d.target.index].name
+ ": " + formatPercent(d.source.value)
+ "\n" + cities[d.target.index].name
+ " → " + cities[d.source.index].name
+ ": " + formatPercent(d.target.value);
});
function mouseover(d, i) {
chord.classed("fade", function(p) {
return p.source.index != i
&& p.target.index != i;
});
}
});
});
</script>
So far, I've flattened the namespaces (up to d3.csv), changed padding to padAngle, and changed var path = d3.chord() to var path = d3.ribbon(). As I make each change, I am checking the error messages in Chrome Developer. After making those changes, the current error is layout.matrix is not a function. This makes sense, based on v4 standards. To combat this, I tried adding .data(layout.matrix) to the var svg creation. I tried a few other routes gleaned from other chord diagram examples, to no avail.
How should I access and bind the data in v4?
Edit: I added .data(layout(matrix)) instead, and now the g elements with class=group are being created. However, this error is occurring: attribute d: Expected number, "MNaN,NaNLNaN,NaNZ". So I'm thinking this means the location is not being populated correctly.
Edit #2: Now I've gotten everything to show up except for the bars around the outside. Here is my current code. I believe the d attribute of the path elements within the g groups are wrong. They are set to be the same as the path elements outside the g groups. When I attempt to set them to arc instead (.attr("d", arc), the error attribute d: Expected number, "MNaN,NaNLNaN,NaNZ". occurs.
<script>
var width = 900,
height = 900,
outerRadius = Math.min(width, height) / 2 - 10,
innerRadius = outerRadius - 24;
var formatPercent = d3.format(",.0f");
var arc = d3.arc()
.innerRadius(innerRadius)
.outerRadius(outerRadius);
var layout = d3.chord()
.padAngle(.02)
.sortSubgroups(d3.descending)
.sortChords(d3.ascending);
var ribbon = d3.ribbon()
.radius(innerRadius);
var svg = d3.select("body")
.append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("id", "circle")
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")")
svg.append("circle")
.attr("r", outerRadius);
d3.csv("teams.csv", function(cities) {
d3.json("matrix.json", function(matrix) {
// Add a group per neighborhood.
var group = svg.selectAll(".group")
.data(layout(matrix))
.enter()
.append("g")
.attr("class", "group");
// Add the group arc.
var groupRibbon = group.append("path")
.attr("id", function(d, i) { return "group" + i; })
.attr("d", ribbon)
//.style("fill", function(d, i) { return cities[i].color; })
;
// Add the chords.
var chord = svg.selectAll(".chord")
.data(layout(matrix))
.enter().append("path")
.attr("class", "chord")
.style("fill", function(d) { return cities[d.source.index].color; })
.attr("d", ribbon);
});
});
</script>

Why my D3 line graphs shows black areas for each entity?

I made a webscraper that gets data about currency transfer rates of different banks and shows that in a D3 line graph over time (each bank has a line, and the rates are per day). A cronjob server-side makes sure the scraping occurs daily.
In the front-end, it uses D3.json to get data from this url:
http://rateswebscraper.herokuapp.com/rates
I made the line graph but instead of a line for every bank, it shows a black area, see screenshot below:
Here is my code:
/*global d3*/
var margin = {
top: 20,
right: 50,
bottom: 20,
left: 50
};
var w = 1000 - margin.left - margin.right,
h = 500 - margin.top - margin.bottom;
var ratesData = "http://rateswebscraper.herokuapp.com/rates";
//load buy or sell data
var loadData = function(dataSet, title) {
//set chart title
document.getElementById("title").innerHTML = title;
//reset SVG container element
d3.select("#chart").select("svg").remove();
var svg = d3.select("#chart")
.append("svg")
.attr("width", w + margin.left + margin.right)
.attr("height", h + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")")
.attr("id", "area");
//Create the scales
var x = d3.scaleTime().range([0, w]),
y = d3.scaleLinear().range([h, 0]),
z = d3.scaleOrdinal(d3.schemeCategory10);
//Line generator for path
var line = d3.line()
.x(function(d) {
return x(d.date);
})
.y(function(d) {
return y(d.rate);
});
d3.json(ratesData, function(data) {
//convert date strings bank to date objects for d3.scaleTime
var rates = data.map(function(item) {
item.date = new Date(item.date);
return item;
});
var banks = rates[0].data.map(function(item) {
//loop through the .data array and get the bank names for the series
var bank = {};
bank.id = item.name;
bank.values = [];
return bank;
});
var createRates = function(type) {
rates.forEach(function(item) {
item.data.forEach(function(rate) {
for (var i = 0; i < banks.length; i++) {
if (banks[i].id === rate.name) {
var rateObject = {};
rateObject.date = new Date(item.date);
if (type === "buy") {
rateObject.rate = Number(rate.buy);
} else {
rateObject.rate = Number(rate.sell);
}
banks[i].values.push(rateObject);
}
}
});
});
};
//Create a rates array per bank of buy values
if (dataSet === "buy") {
createRates("buy");
} else {
createRates("sell");
}
//Get the Min/Max values for date and rates and setup color scale based on bank ID
x.domain(d3.extent(rates, function(d) {
return d.date;
}));
y.domain([
d3.min(banks, function(c) {
return d3.min(c.values, function(d) {
if (d.rate !== 0) {
return d.rate;
} else {
return
}
});
}),
d3.max(banks, function(c) {
return d3.max(c.values, function(d) {
return d.rate;
});
})
]);
//color scale needs an array of bank id's
z.domain(banks.map(function(c) {
return c.id;
}));
//append x Axis
svg.append("g")
.attr("class", "axis axis--x")
.attr("transform", "translate(0," + h + ")")
.call(d3.axisBottom(x));
//append y Axis
svg.append("g")
.attr("class", "axis axis--y")
.call(d3.axisLeft(y))
.append("text")
.attr("transform", "rotate(-90)")
.attr("y", 6)
.attr("dy", "0.71em")
.attr("fill", "#000")
.text("Rates in HKD");
//for every bank element we append a g group element
var bank = svg.selectAll(".bank")
.data(banks)
.enter().append("g")
.attr("class", "bank");
//for every bank element we append a path element and use the line generator
bank.append("path")
.attr("class", "line")
.attr("d", function(d) {
return line(d.values);
})
.style("stroke", function(d) {
return z(d.id);
});
//append a text next to the line for every bank
bank.append("text")
.datum(function(d) {
return {
id: d.id,
value: d.values[d.values.length - 1]
};
})
.attr("transform", function(d) {
return "translate(" + x(d.value.date) + "," + y(d.value.rate) + ")";
})
.attr("x", 3)
.attr("dy", "0.35em")
.style("font", "10px work sans")
.text(function(d) {
return d.id;
});
}); =
};
//Call loadData function on page load with buy rates
loadData("buy", "Buy Rates");
//Add click events to buttons to load buy or sell data
document.getElementById("buyData").addEventListener("click", function() {
loadData("buy", "Buy Rates");
});
document.getElementById("sellData").addEventListener("click", function() {
loadData("sell", "Sell Rates");
})
Anyone can help me what I am doing wrong in my code?

Add a style to the path:
.style("fill","none");

Prevent loop in D3js Sankey chart

I'm trying to create a sankey chart using the d3 sankey plugin with dynamic shipping data. It works great most of the time except when I get a data set like this:
[{"DeparturePort":"CHARLESTON","ArrivalPort":"BREMERHAVEN","volume":5625.74},{"DeparturePort":"CHARLESTON","ArrivalPort":"ITAPOA","volume":2340},{"DeparturePort":"PT EVERGLADES","ArrivalPort":"PT AU PRINCE","volume":41.02},{"DeparturePort":"BREMERHAVEN","ArrivalPort":"CHARLESTON","volume":28}]
The key to my issue is the first and last entry in the data set. It seems that having opposite directions in the same sankey chart sends the javascript into an infinite loop and kills the browser. Any ideas on how to prevent this from happening?
Here's my chart code where raw would be the object above:
var data = raw;
var units = "Volume";
var margin = { top: 100, right: 0, bottom: 30, left: 0 },
width = $("#"+divID).width() - margin.left - margin.right,
height = divID == "enlargeChart" ? 800 - margin.top - margin.bottom : 600 - margin.top - margin.bottom;
var formatNumber = d3.format(",.0f"), // zero decimal places
format = function (d) { return ""; },
color = d3.scale.ordinal()
.range(["#0077c0", "#FF6600"]);
// append the svg canvas to the page
var svg = d3.select("#"+divID).append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.style("font-size", "12px")
.append("g")
.attr("transform",
"translate(" + margin.left + "," + margin.top + ")");
// Set the sankey diagram properties
var sankey = d3.sankey(width)
.nodeWidth(10)
.nodePadding(10)
.size([width, height]);
var path = sankey.link();
// load the data (using the timelyportfolio csv method)
//d3.csv("sankey.csv", function (error, data) {
//set up graph in same style as original example but empty
graph = { "nodes": [], "links": [] };
var checklist = [];
data.forEach(function (d) {
if ($.inArray(d.DeparturePort, checklist) == -1) {
checklist.push(d.DeparturePort)
graph.nodes.push({ "name": d.DeparturePort });
}
if ($.inArray(d.ArrivalPort, checklist) == -1) {
checklist.push(d.ArrivalPort)
graph.nodes.push({ "name": d.ArrivalPort });
}
graph.links.push({
"source": d.DeparturePort,
"target": d.ArrivalPort,
"value": +d.volume
});
});
// return only the distinct / unique nodes
graph.nodes = d3.keys(d3.nest()
.key(function (d) { return d.name; })
.map(graph.nodes));
// loop through each link replacing the text with its index from node
graph.links.forEach(function (d, i) {
graph.links[i].source = graph.nodes.indexOf(graph.links[i].source);
graph.links[i].target = graph.nodes.indexOf(graph.links[i].target);
});
//now loop through each nodes to make nodes an array of objects
// rather than an array of strings
graph.nodes.forEach(function (d, i) {
graph.nodes[i] = { "name": d };
});
sankey
.nodes(graph.nodes)
.links(graph.links)
.layout(32);
// add in the links
var link = svg.append("g").selectAll(".link")
.data(graph.links)
.enter().append("path")
.attr("class", "link")
.attr("d", path)
.style("stroke-width", function (d) { return Math.max(1, d.dy); })
.sort(function (a, b) { setTimeout(function () { return b.dy - a.dy; }, 10);});
// add the link titles
link.append("title")
.text(function (d) {
return d.source.name + " → " +
d.target.name + "\n" + d.value.toFixed(0) + " TEU";
});
$("#" + divID + " .loading").addClass("hide");
// add in the nodes
var node = svg.append("g").selectAll(".node")
.data(graph.nodes)
.enter().append("g")
.attr("class", "node")
.attr("transform", function (d) {
//setTimeout(function () {
return "translate(" + d.x + "," + d.y + ")";
//}, 10);
})
.call(d3.behavior.drag()
.origin(function (d) { return d; })
.on("dragstart", function () {
this.parentNode.appendChild(this);
})
.on("drag", dragmove));
// add the rectangles for the nodes
node.append("rect")
.attr("height", function (d) { if (d.dy < 0) { d.dy = (d.dy * -1); } return d.dy; })
.attr("width", sankey.nodeWidth())
.style("fill", function (d) {
return d.color = color(d.name);
})
.style("stroke", function (d) {
return d3.rgb(d.color);
})
.append("title")
.text(function (d) {
return d.name + "\n" + format(d.value);
});
// add in the title for the nodes
node.append("text")
.attr("x", -6)
.attr("y", function (d) { return d.dy / 2; })
.attr("dy", ".35em")
.attr("text-anchor", "end")
.style("stroke", function (d) { return "#000000" })
.attr("transform", null)
.text(function (d) { return d.name; })
.filter(function (d) { return d.x < width / 2; })
.attr("x", 6 + sankey.nodeWidth())
.attr("text-anchor", "start");
// the function for moving the nodes
function dragmove(d) {
d3.select(this).attr("transform",
"translate(" + d.x + "," + (
d.y = Math.max(0, Math.min(height - d.dy, d3.event.y))
) + ")");
sankey.relayout();
link.attr("d", path);
}
}, 0)

It's an issue with the sankey.js script.
See this commit (on a fork of sankey.js) which fixed it:
https://github.com/soxofaan/d3-plugin-captain-sankey/commit/0edba18918aac3e9afadffd4a169c47f88a98f81
while (remainingNodes.length) {
becomes:
while (remainingNodes.length && x < nodes.length) {
That should prevent the endless loop.

How to add a list of node's name with tooltip in sankey

I have made a sankey diagram with rChars package in R.
But I want to add a function, when we move to a link or a target node, it will show all the names of source node in a tooltip (or a new box at the right top of the graph).
For example, it will show "ddd.fr, pramana.fr" when we move to the node "target1".
I'm new in d3.js and know little about svg attribute. I have tried to do something with "link.append("title").text" or "node.append("title").text". But what I have done seem to be no use, because the function(d) always return one data but not an array.
Here is my code, hope someone can help, thanks !
<!doctype HTML>
<meta charset = 'utf-8'>
<html>
<head>
<link rel='stylesheet' href='http://timelyportfolio.github.io/rCharts_d3_sankey/css/sankey.css'>
<script src='http://timelyportfolio.github.io/rCharts_d3_sankey/js/d3.v3.js' type='text/javascript'></script>
<script src='http://timelyportfolio.github.io/rCharts_d3_sankey/js/sankey.js' type='text/javascript'></script>
<style>
.rChart {
display: block;
margin-left: auto;
margin-right: auto;
width: 900px;
height: 1000px;
}
</style>
</head>
<body >
<div id = 'chart202c4a213951' class = 'rChart rCharts_d3_sankey'></div>
<!--Attribution:
Mike Bostock https://github.com/d3/d3-plugins/tree/master/sankey
Mike Bostock http://bost.ocks.org/mike/sankey/
-->
<script>
(function(){
var params = {
"dom": "chart202c4a213951",
"width": 800,
"height": 300,
"data": {
"source": [ "A.fr", "B.fr", "C.fr", "ddd.fr", "pramana.fr", "pramana.fr" ],
"target": [ "pramana.fr", "pramana.fr", "ddd.fr", "target1", "target1", "target2" ],
"cat": [ 0, 1, 0, 1, 0, -1 ] ,
"value": [ 1, 1, 1, 1, 1, 1]
},
"nodeWidth": 15,
"nodePadding": 10,
"layout": 32,
"units": "freq",
"title": "Sankey Diagram pramana",
"id": "chart202c4a213951"
};
params.units ? units = " " + params.units : units = "";
//hard code these now but eventually make available
var formatNumber = d3.format("0,.0f"), // zero decimal places
format = function(d) { return formatNumber(d) + units; },
color = d3.scale.category20();
if(params.labelFormat){
formatNumber = d3.format(".2%");
}
var svg = d3.select('#' + params.id).append("svg")
.attr("width", params.width)
.attr("height", params.height);
var sankey = d3.sankey()
.nodeWidth(params.nodeWidth)
.nodePadding(params.nodePadding)
.layout(params.layout)
.size([params.width,params.height]);
var path = sankey.link();
var data = params.data,
links = [],
nodes = [];
//get all source and target into nodes
//will reduce to unique in the next step
//also get links in object form
data.source.forEach(function (d, i) {
nodes.push({ "name": data.source[i] });
nodes.push({ "name": data.target[i] });
links.push({ "source": data.source[i], "target": data.target[i], "value": +data.value[i] });
});
//now get nodes based on links data
//thanks Mike Bostock https://groups.google.com/d/msg/d3-js/pl297cFtIQk/Eso4q_eBu1IJ
//this handy little function returns only the distinct / unique nodes
nodes = d3.keys(d3.nest()
.key(function (d) { return d.name; })
.map(nodes));
//it appears d3 with force layout wants a numeric source and target
//so loop through each link replacing the text with its index from node
links.forEach(function (d, i) {
links[i].source = nodes.indexOf(links[i].source);
links[i].target = nodes.indexOf(links[i].target);
});
//now loop through each nodes to make nodes an array of objects rather than an array of strings
nodes.forEach(function (d, i) {
nodes[i] = { "name": d };
});
sankey
.nodes(nodes)
.links(links)
.layout(params.layout);
var link = svg.append("g").selectAll(".link")
.data(links)
.enter().append("path")
.attr("class", "link")
.attr("d", path)
.style("stroke-width", function (d) { return Math.max(1, d.dy); })
.sort(function (a, b) { return b.dy - a.dy; });
link.append("title")
.text(function (d) { return d.source.name + " → " + d.target.name + "\n" + format(d.value); });
var node = svg.append("g").selectAll(".node")
.data(nodes)
.enter().append("g")
.attr("class", "node")
.attr("transform", function (d) { return "translate(" + d.x + "," + d.y + ")"; })
.call(d3.behavior.drag()
.origin(function (d) { return d; })
.on("dragstart", function () { this.parentNode.appendChild(this); })
.on("drag", dragmove));
node.append("rect")
.attr("height", function (d) { return d.dy; })
.attr("width", sankey.nodeWidth())
.style("fill", function (d) { return d.color = color(d.name.replace(/ .*/, "")); })
.style("stroke", function (d) { return d3.rgb(d.color).darker(2); })
.append("title")
.text(function (d) { return d.name + "\n" + format(d.value); });
node.append("text")
.attr("x", -6)
.attr("y", function (d) { return d.dy / 2; })
.attr("dy", ".35em")
.attr("text-anchor", "end")
.attr("transform", null)
.text(function (d) { return d.name; })
.filter(function (d) { return d.x < params.width / 2; })
.attr("x", 6 + sankey.nodeWidth())
.attr("text-anchor", "start");
// the function for moving the nodes
function dragmove(d) {
d3.select(this).attr("transform",
"translate(" + (
d.x = Math.max(0, Math.min(params.width - d.dx, d3.event.x))
) + "," + (
d.y = Math.max(0, Math.min(params.height - d.dy, d3.event.y))
) + ")");
sankey.relayout();
link.attr("d", path);
}
})();
</script>
</body>
</html>

In your function that is supposed to retrieve names of other nodes that are "source" (or"target", implementation would be the same) to the current node, you can do something like this:
function(d,i){
d.sourceLinks.forEach(function(srcLnk){
// find the name of the other end of the link
});
d.targetLinks.forEach(function(tgtLnk){
// find the name of the other end of the link
});
}
In other words, use d.sourceLinks and d.targetLinks. And you gradually add names one by one, and display wherever you find suitable (tooltip, separate box, etc.).
In turn, each link has property source and target, and you can use something like srcLnk.source.name to obtain the name of one of the nodes that is a "source" for the current node.
I am writing this by hearth, so double check everything, some properties may have differeent name than I said.
Hope this helps.
UPDATE: jsfiddle
Key code:
.append("title")
.text(function (d) {
var titleText = d.name + " - " +
format(d.value) + " total" + "\n" + "\n";
var sourcesText = "";
d.targetLinks.forEach(function(dstLnk){
sourcesText += "from " + dstLnk.source.name + " - " +
format(dstLnk.value) + "\n";
});
return titleText + sourcesText;
});

Triggering two separate events on mouseover in D3

I have a D3 bar chart with the associated data points displayed as text on top of each bar. I want to display the text only on mouseover and also make the bar have a different fill color. So, essentially, on mouseover, the bar has to be styled to have a different fill color and the text opacity should go to 1 (from '0').
I am having trouble effecting two separate events on mouseover. I have given an index_value attribute to both elements in order to use d3.select(this).attr(index_value). But my mouseover function does not work. I have no idea why. Here's my relevant code section.
The bar chart
svg.selectAll(".bar")
.data(data)
.enter().append("rect")
.attr('data-value', function(d){return d[region]})
.attr("x", function(d) { return x(d.year); })
.attr("width", x.rangeBand())
.attr("y", function(d) { return y(d[region]); })
.attr("height", function(d) { return height - y(d[region]); })
.attr("fill", color)
.attr("index_year", function(d, i) { return "index-" + d.year; })
.attr("class", function(d){return "bar " + "bar-index-" + d.year;})
.attr("color_value", color)
.on('mouseover', synchronizedMouseOver)
.on("mouseout", synchronizedMouseOut);
The text overlay
svg.selectAll(".bartext")
.data(data)
.enter()
.append("text")
.attr("text-anchor", "middle")
.attr("x", function(d,i) {
return x(d.year)+x.rangeBand()/2;
})
.attr("y", function(d,i) {
return height - (height - y(d[region])) - yTextPadding;
})
.text(function(d){
return d3.format(prefix)(d3.round(d[region]));
})
.attr("index_year", function(d, i) { return "index-" + d.year; })
.attr("class", function(d){return "bartext " + "label-index-" + d.year;})
.on("mouseover", synchronizedMouseOver)
.on("mouseout", synchronizedMouseOut);
And the mouseover function
var synchronizedMouseOver = function() {
var bar = d3.select(this);
console.log(bar);
var indexValue = bar.attr("index_year");
var barSelector = "." + "bar " + "bar-" + indexValue;
var selectedBar = d3.selectAll(barSelector);
selectedBar.style("fill", "#f7fcb9");
var labelSelector = "." + "bartext " + "label-" + indexValue;
var selectedLabel = d3.selectAll(labelSelector);
selectedLabel.style("opacity", "1");
};

This can be achieved by simplifying your listeners. You don't need to add listeners to both rects and text. Just add them to the rects. Here are the simplified listeners:
function synchronizedMouseOver(d) {
var bar = d3.select(this)
.style("fill","red");
var text = d3.select(".label-index-" + d.year)
.style("opacity","1");
};
function synchronizedMouseOut(d) {
var bar = d3.select(this)
.style("fill",color);
var text = d3.select(".label-index-" + d.year)
.style("opacity","0");
};
Your two friends here are this and d, the DOM element for the rect and its data node, respectively.
Here is a FIDDLE with the behavior that you desire.