We Keep Coding

Updating D3 bubble radius with collide simulation

I've been wrestling very hard with D3 to try to make a simple bubble-chart using force collide that live-updates the bubble size.
I can get the chart to show on the first data update with force collide. However subsequent data calls freeze the chart and the sizes are never updated:
https://jsfiddle.net/d2zcfjfa/1/
node = svg.selectAll('g.node')
.data(root.children)
.enter()
.append('g')
.attr('class', 'node')
.append('circle')
.attr('r', function(d) { return d.r * 1.4; })
.attr('fill', function(d) { return color(d.data.name); })
.call(d3.drag()
.on("start", dragStart)
.on("drag", dragged)
.on("end", dragEnd));
var circleUpdate = node.select('circle')
.attr('r', function(d)
{
return d.r;
});
simulation.nodes(root.children);
I can get updates to work but only without using the collide simulation as seen here:
https://jsfiddle.net/rgdox7g7/1/
node = svg.selectAll('g.node')
.data(root.children)
.enter()
.append('g')
.attr('id', function(d) { return d.id; })
.attr('class', 'node')
.attr('transform', function(d)
{
return "translate(" + d.x + "," + d.y + ")";
});
var nodeUpdate = svg.selectAll('g.node')
.transition()
.duration(2000)
.ease(d3.easeLinear);
var circleUpdate = nodeUpdate.select('circle')
.attr('r', function(d)
{
return d.r;
});
node.append("circle")
.attr("r", function(d) { return d.r; })
.style('fill', function(d) { return color(d.data.name); });
Everything I have tried to mix these two solutions together simply does not work. I have scoured the internet for other examples and nothing I can find is helping. Can someone please help me understand what to do? I never thought D3 would be such a frustration!

stackoverflow: the place where you have to answer your own questions.
here is my working solution:
https://jsfiddle.net/zc0fgh6y/
var subscription = null;
var width = 600;
var height = 300;
var maxSpeed = 1000000;
var pack = d3.pack().size([width, height]).padding(0);
var svg = d3.select('svg');
var node = svg.selectAll("g.node");
var root;
var nodes = [];
var first = true;
var scaleFactor = 1.4;
var color = d3.interpolateHcl("#0faac3", "#dd2323");
var forceCollide = d3.forceCollide()
.strength(.8)
.radius(function(d)
{
return d.r;
}).iterations(10);
var simulationStart = d3.forceSimulation()
.force("forceX", d3.forceX(width/2).strength(.04))
.force("forceY", d3.forceY(height/2).strength(.2))
.force('collide', forceCollide)
.on('tick', ticked);
var simulation = d3.forceSimulation()
.force("forceX", d3.forceX(width/2).strength(.0005))
.force("forceY", d3.forceY(height/2).strength(.0025))
.force('collide', forceCollide)
.on('tick', ticked);
function ticked()
{
if (node)
{
node.attr('transform', function(d)
{
return "translate(" + d.x + "," + d.y + ")";
}).select('circle').attr('r', function(d)
{
return d.r;
});
}
}
function rand(min, max)
{
return Math.random() * (max - min) + min;
};
setInterval(function()
{
var hosts = [];
for (var i = 0; i < 100; i++)
{
hosts.push({name: i, cpu: rand(10,100), speed: rand(0,maxSpeed)});
}
root = d3.hierarchy({children: hosts})
.sum(function(d)
{
return d.cpu ? d.cpu : 0;
});
var leaves = pack(root).leaves().map(function(item)
{
return {
id: 'node-'+item.data.name,
name: item.data.name,
r: item.r * scaleFactor,
x: width/2,
y: height/2,
cpu: item.data.cpu,
speed: item.data.speed
};
});
for (var i = 0; i < leaves.length; i++)
{
if (nodes[i] && nodes[i].id == leaves[i].id)
{
var oldR = nodes[i].newR;
nodes[i].oldR = oldR;
nodes[i].newR = leaves[i].r;
nodes[i].cpu = leaves[i].cpu;
nodes[i].speed = leaves[i].speed;
}
else
{
nodes[i] = leaves[i];
//nodes[i].r = 1;
nodes[i].oldR = 1;//nodes[i].r;
nodes[i].newR = leaves[i].r;
}
}
if (first)
{
first = false;
node = node.data(nodes, function(d) { return d.id; });
node = node.enter()
.append('g')
.attr('class', 'node');
node.append("circle")
.style("fill", 'transparent');
node.append("text")
.attr("dy", "0.3em")
.style('fill', 'transparent')
.style("text-anchor", "middle")
.text(function(d)
{
return d.name;//.substring(0, d.r / 4);
});
// transition in size
node.transition()
.ease(d3.easePolyInOut)
.duration(950)
.tween('radius', function(d)
{
var that = d3.select(this);
var i = d3.interpolate(1, d.newR);
return function(t)
{
d.r = i(t);
that.attr('r', function(d)
{
return d.r;
});
simulationStart.nodes(nodes).alpha(1);
}
});
// fade in text color
node.select('text')
.transition()
.ease(d3.easePolyInOut)
.duration(950)
.style('fill', 'white');
// fade in circle size
node.select('circle')
.transition()
.ease(d3.easePolyInOut)
.duration(950)
.style('fill', function(d)
{
return color(d.speed / maxSpeed);
});
}
else
{
// transition to new size
node.transition()
.ease(d3.easeLinear)
.duration(950)
.tween('radius', function(d)
{
var that = d3.select(this);
var i = d3.interpolate(d.oldR, d.newR);
return function(t)
{
d.r = i(t);
that.attr('r', function(d)
{
return d.r;
});
simulation.nodes(nodes).alpha(1);
}
});
// transition to new color
node.select('circle')
.transition()
.ease(d3.easeLinear)
.duration(950)
.style('fill', function(d)
{
return color(d.speed / maxSpeed);
});
}
}, 1000);

Dynamically update D3 Sunburst if the source json is updated (item added or deleted)

I am new to D3 and trying to dynamically update the chart if the source json is modified. But I am not able to achieve this.
Please check this plunkr
Js:
var width = 500,
height = 500,
radius = Math.min(width, height) / 2;
var x = d3.scale.linear()
.range([0, 2 * Math.PI]);
var y = d3.scale.sqrt()
.range([0, radius]);
var color = d3.scale.category10();
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("transform", "translate(" + width / 2 + "," + (height / 2 + 10) + ") rotate(-90 0 0)");
var partition = d3.layout.partition()
.value(function(d) {
return d.size;
});
var arc = d3.svg.arc()
.startAngle(function(d) {
return Math.max(0, Math.min(2 * Math.PI, x(d.x)));
})
.endAngle(function(d) {
return Math.max(0, Math.min(2 * Math.PI, x(d.x + d.dx)));
})
.innerRadius(function(d) {
return Math.max(0, y(d.y));
})
.outerRadius(function(d) {
return Math.max(0, y(d.y + d.dy));
});
//d3.json("/d/4063550/flare.json", function(error, root) {
var root = initItems;
var g = svg.selectAll("g")
.data(partition.nodes(root))
.enter().append("g");
var path = g.append("path")
.attr("d", arc)
.style("fill", function(d) {
return color((d.children ? d : d.parent).name);
})
.on("click", click)
.each(function(d) {
this.x0 = d.x;
this.dx0 = d.dx;
});
//.append("text")
var text = g.append("text")
.attr("x", function(d) {
return y(d.y);
})
.attr("dx", "6") // margin
.attr("dy", ".35em") // vertical-align
.attr("transform", function(d) {
return "rotate(" + computeTextRotation(d) + ")";
})
.text(function(d) {
return d.name;
})
.style("fill", "white");
function computeTextRotation(d) {
var angle = x(d.x + d.dx / 2) - Math.PI / 2;
return angle / Math.PI * 180;
}
function click(d) {
console.log(d)
// fade out all text elements
if (d.size !== undefined) {
d.size += 100;
};
text.transition().attr("opacity", 0);
path.transition()
.duration(750)
.attrTween("d", arcTween(d))
.each("end", function(e, i) {
// check if the animated element's data e lies within the visible angle span given in d
if (e.x >= d.x && e.x < (d.x + d.dx)) {
// get a selection of the associated text element
var arcText = d3.select(this.parentNode).select("text");
// fade in the text element and recalculate positions
arcText.transition().duration(750)
.attr("opacity", 1)
.attr("transform", function() {
return "rotate(" + computeTextRotation(e) + ")"
})
.attr("x", function(d) {
return y(d.y);
});
}
});
} //});
// Word wrap!
var insertLinebreaks = function(t, d, width) {
alert(0)
var el = d3.select(t);
var p = d3.select(t.parentNode);
p.append("g")
.attr("x", function(d) {
return y(d.y);
})
// .attr("dx", "6") // margin
//.attr("dy", ".35em") // vertical-align
.attr("transform", function(d) {
return "rotate(" + computeTextRotation(d) + ")";
})
//p
.append("foreignObject")
.attr('x', -width / 2)
.attr("width", width)
.attr("height", 200)
.append("xhtml:p")
.attr('style', 'word-wrap: break-word; text-align:center;')
.html(d.name);
alert(1)
el.remove();
alert(2)
};
//g.selectAll("text")
// .each(function(d,i){ insertLinebreaks(this, d, 50 ); });
d3.select(self.frameElement).style("height", height + "px");
// Interpolate the scales!
function arcTween(d) {
var xd = d3.interpolate(x.domain(), [d.x, d.x + d.dx]),
yd = d3.interpolate(y.domain(), [d.y, 1]),
yr = d3.interpolate(y.range(), [d.y ? 20 : 0, radius]);
return function(d, i) {
return i ? function(t) {
return arc(d);
} : function(t) {
x.domain(xd(t));
y.domain(yd(t)).range(yr(t));
return arc(d);
};
};
}
function arcTweenUpdate(a) {
console.log(path);
var _self = this;
var i = d3.interpolate({ x: this.x0, dx: this.dx0 }, a);
return function(t) {
var b = i(t);
console.log(window);
_self.x0 = b.x;
_self.dx0 = b.dx;
return arc(b);
};
}
setTimeout(function() {
path.data(partition.nodes(newItems))
.transition()
.duration(750)
.attrTween("d", arcTweenUpdate)
}, 2000);

In addition to what #Cyril has suggested about removing the following line:
d3.select(self.frameElement).style("height", height + "px");
I made further modifications in your fiddle: working fiddle
The idea used here is to add a function updateChart which takes the items and then generate the chart:
var updateChart = function (items) {
// code to update the chart with new items
}
updateChart(initItems);
setTimeout(function () { updateChart(newItems); }, 2000);
This doesn't use the arcTweenUpdate function you have created but I will try to explain the underlying concept:
First, you will need to JOIN the new data with your existing data:
// DATA JOIN - Join new data with old elements, if any.
var gs = svg.selectAll("g").data(partition.nodes(root));
then, ENTER to create new elements if required:
// ENTER
var g = gs.enter().append("g").on("click", click);
But, we also need to UPDATE the existing/new path and text nodes with new data:
// UPDATE
var path = g.append("path");
gs.select('path')
.style("fill", function(d) {
return color((d.children ? d : d.parent).name);
})
//.on("click", click)
.each(function(d) {
this.x0 = d.x;
this.dx0 = d.dx;
})
.transition().duration(500)
.attr("d", arc);
var text = g.append("text");
gs.select('text')
.attr("x", function(d) {
return y(d.y);
})
.attr("dx", "6") // margin
.attr("dy", ".35em") // vertical-align
.attr("transform", function(d) {
return "rotate(" + computeTextRotation(d) + ")";
})
.text(function(d) {
return d.name;
})
.style("fill", "white");
and, after everything is created/updated remove the g nodes which are not being used i.e. EXIT:
// EXIT - Remove old elements as needed.
gs.exit().transition().duration(500).style("fill-opacity", 1e-6).remove();
This whole pattern of JOIN + ENTER + UPDATE + EXIT is demonstrated in following articles by Mike Bostock:
General Update Pattern - I
General Update Pattern - II
General Update Pattern - III

In side the fiddle the setTimeout is not running because:
d3.select(self.frameElement).style("height", height + "px");
You will get Uncaught SecurityError: Failed to read the 'frame' property from 'Window': Blocked a frame with origin "https://fiddle.jshell.net" from accessing a frame with origin and the setTimeout never gets called.
So you can remove this line d3.select(self.frameElement).style("height", height + "px"); just for the fiddle.
Apart from that:
Your timeout function should look like this:
setTimeout(function() {
//remove the old graph
svg.selectAll("*").remove();
root = newItems;
g = svg.selectAll("g")
.data(partition.nodes(newItems))
.enter().append("g");
/make path
path = g.append("path")
.attr("d", arc)
.style("fill", function(d) {
return color((d.children ? d : d.parent).name);
})
.on("click", click)
.each(function(d) {
this.x0 = d.x;
this.dx0 = d.dx;
});
//make text
text = g.append("text")
.attr("x", function(d) {
return y(d.y);
})
.attr("dx", "6") // margin
.attr("dy", ".35em") // vertical-align
.attr("transform", function(d) {
return "rotate(" + computeTextRotation(d) + ")";
})
.text(function(d) {
return d.name;
})
.style("fill", "white");
}
working fiddle here

for the enter() and transitions to work you need to give d3 a way to identify each item in your data. the .data() function has a second parameter that lets you return something to use as an id. enter() will use the id to decide whether the object is new.
try changing
path.data(partition.nodes(newItems))
.data(partition.nodes(root));
to
path.data(partition.nodes(newItems), function(d){return d.name});
.data(partition.nodes(root), function(d){return d.name});

d3.js pie chart Invalid value for <path> attribute

I am begginer to d3.js and getting errors, I customized the example for my needs but gettings these in the console. Please help. Thank you in Advance.
Error: Invalid value for <path> attribute d="M-1.8369701987210297e-14,-100A100,100 0 1,1 NaN,NaNLNaN,NaNA60,60 0 1,0 -1.1021821192326178e-14,-60Z"a # d3.v3.min.js:1
d3.v3.min.js:1 Error: Invalid value for <path> attribute d="MNaN,NaNA100,100 0 1,1 NaN,NaNLNaN,NaNA60,60 0 1,0 NaN,NaNZ"
var getData = function () {
var size = 3;
var data =[];
var text = "";
data=[
{
label:"Saved",
value:200,
},{
label:"Ordered",
value:1255,
},{
label:"Shipped",
value:760,
},{
label:"Backordered",
value:150,
},
{
label:"Cancelled",
value:250,
},
];
d3.select("#data").html(text);
return data;
};
console.log(getData());
var chart = donut(250,200,16,40)
.$el(d3.select("#chart"))
.data(getData())
.render();
d3.select("#refresh").on("click", function () {
chart.data(getData()).render();
});
function donut(width,height,label_font_size,value_font_size) {
// Default settings
var $el = d3.select("body")
var data = {};
// var showTitle = true;
var width = width,
height = height,
radius = Math.min(width, height) / 2;
//var arc = d3.svg.arc().outerRadius(radius);
var arcOver = d3.svg.arc()
.innerRadius(radius + 20);
var currentVal;
var color = d3.scale.category20();
var pie = d3.layout.pie()
.sort(null)
.value(function (d) {
console.log(d);
return d.value.value;
});
var svg, g, arc;
var object = {};
// Method for render/refresh graph
object.render = function () {
if (!svg) {
arc = d3.svg.arc()
.outerRadius(radius)
.innerRadius(radius - (radius / 2.5));
svg = $el.append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");
g = svg.selectAll(".arc")
.data(pie(d3.entries(data)))
.enter().append("g")
.attr("class", "arc");
g.append("path")
// Attach current value to g so that we can use it for animation
.each(function (d) {
//this._current = d;
})
.attr("d", arc)
.style("fill", function (d,i) {
return color(i);
});
/*g.append("text")
.attr("transform", function (d,i) {
return "translate(" + arc.centroid(d,i) + ")";
})
.attr("dy", ".35em")
.style("text-anchor", "middle");
g.select("text").text(function (d) {
//return d.data.key;
});
*/
svg.append("text")
.datum(data)
.attr("x", 0)
.attr("y", 0)
.attr("class", "text-tooltip")
.style("text-anchor", "middle")
.attr("font-weight", "bold")
.style("font-size", radius / 2.5 + "px");
g.on("mouseover", function (obj) {
var tooltipText=svg.select("text.text-tooltip");
tooltipText.attr("fill", function (d,i) {
return color(i);
});
tooltipText.append("tspan")
.attr("dy", -15)
.attr("x",0)
.attr("class", "text-tooltip-label")
.style("font-size", label_font_size + "px")
.text(function(d) {return d[obj.data.key].label;});
tooltipText.append("tspan")
.attr("dy", ".9em") // offest by 1.2 em
.attr("x",0)
.attr("class", "text-tooltip-value")
.style("font-size", value_font_size + "px")
.text(function(d) {return d[obj.data.key].value;});
d3.select(this)
.attr("stroke","white")
.transition()
.duration(1000)
.attr("d", arcOver)
.attr("stroke-width",6);
});
g.on("mouseout", function (obj) {
svg.select("text.text-tooltip").text("");
d3.select(this).transition()
.attr("d", arc)
.attr("stroke","none");
});
} else {
g.data(pie(d3.entries(data))).exit().remove();
g.select("path")
.transition().duration(200)
.attrTween("d", function (a) {
var i = d3.interpolate(this._current, a);
this._current = i(0);
return function (t) {
return arc(i(t));
};
});
g.select("text")
.attr("transform", function (d,i) {
return "translate(" + arc.centroid(d,i) + ")";
});
svg.select("text.text-tooltip").datum(data);
}
return object;
};
// Getter and setter methods
object.data = function (value) {
if (!arguments.length) return data;
data = value;
return object;
};
object.$el = function (value) {
if (!arguments.length) return $el;
$el = value;
return object;
};
object.width = function (value) {
if (!arguments.length) return width;
width = value;
radius = Math.min(width, height) / 2;
return object;
};
object.height = function (value) {
if (!arguments.length) return height;
height = value;
radius = Math.min(width, height) / 2;
return object;
};
return object;
};
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
<div id="chart"></div>

rotate points from csv on d3 orthogonal projection

I have been trying to project a heat map with data loaded from csv onto a orthogonal projection on D3. While rotating the earth (i.e. D3, orthogonal projection), the points/circles remain static. I have tried many combinations but failed to figure out what is missing.
Basically, i need the small circles move along the path of countries.
Here is the complete code :
<script>
var width = 600,
height = 500,
sens = 0.25,
focused;
//Setting projection
var projection = d3.geo.orthographic()
.scale(245)
.rotate([0,0])
.translate([width / 2, height / 2])
.clipAngle(90);
var path = d3.geo.path()
.projection(projection);
//SVG container
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
// Define the gradient
var gradient = svg.append("svg:defs")
.append("svg:linearGradient")
.attr("id", "gradient")
.attr("x1", "0%")
.attr("y1", "0%")
.attr("x2", "100%")
.attr("y2", "100%")
.attr("spreadMethod", "pad");
// Define the gradient colors
gradient.append("svg:stop")
.attr("offset", "0%")
.attr("stop-color", "#FFFF00")
.attr("stop-opacity", 0);
gradient.append("svg:stop")
.attr("offset", "100%")
.attr("stop-color", "#FF0000")
.attr("stop-opacity", 1);
//Adding water
svg.append("path")
.datum({type: "Sphere"})
.attr("class", "water")
.attr("d", path)
var countryTooltip = d3.select("body").append("div").attr("class", "countryTooltip"),
countryList = d3.select("body").append("select").attr("name", "countries");
queue()
.defer(d3.json, "world-110m.json")
.defer(d3.tsv, "world-110m-country-names.tsv")
.await(ready);
//Main function
function ready(error, world, countryData) {
var countryById = {},
countries = topojson.feature(world, world.objects.countries).features;
//Adding countries to select
countryData.forEach(function(d) {
countryById[d.id] = d.name;
option = countryList.append("option");
option.text(d.name);
option.property("value", d.id);
});
//circles for heatmap are coming from the csv below
d3.csv("cities.csv", function(error, data) {
svg.selectAll("circle")
.data(data)
.enter()
.append("a")
.attr("xlink:href", function(d) {
return "https://www.google.com/search?q="+d.city;}
)
.append("circle")
.attr("cx", function(d) {
return projection([d.lon, d.lat])[0];
})
.attr("cy", function(d) {
return projection([d.lon, d.lat])[1];
})
.attr("r", 5.5)
.attr('fill', 'url(#gradient)');
var world = svg.selectAll("path.circle")
.data(countries) //countries from the tsc file is used to populate the names
.enter().append("path")
.attr("class", "land")
.attr("d", path)
//.attr('fill', 'url(#gradient)')
//Drag event
.call(d3.behavior.drag()
.origin(function() { var r = projection.rotate(); return {x: r[0] / sens, y: -r[1] / sens}; })
.on("drag", function() {
var rotate = projection.rotate();
projection.rotate([d3.event.x * sens, -d3.event.y * sens, rotate[2]]);
svg.selectAll("path.land").attr("d", path);
svg.selectAll(".focused").classed("focused", focused = false);
}))
//Mouse events
.on("mouseover", function(d) {
countryTooltip.text(countryById[d.id])
.style("left", (d3.event.pageX + 7) + "px")
.style("top", (d3.event.pageY - 15) + "px")
.style("display", "block")
.style("opacity", 1);
})
.on("mouseout", function(d) {
countryTooltip.style("opacity", 0)
.style("display", "none");
})
.on("mousemove", function(d) {
countryTooltip.style("left", (d3.event.pageX + 7) + "px")
.style("top", (d3.event.pageY - 15) + "px");
});
});//closing d3.csv here
//Country focus on option select
d3.select("select").on("change", function() {
var rotate = projection.rotate(),
focusedCountry = country(countries, this),
p = d3.geo.centroid(focusedCountry);
svg.selectAll(".focused").classed("focused", focused = false);
//Globe rotating
(function transition() {
d3.transition()
.duration(2500)
.tween("rotate", function() {
var r = d3.interpolate(projection.rotate(), [-p[0], -p[1]]);
return function(t) {
projection.rotate(r(t));
svg.selectAll("path").attr("d", path)
.classed("focused", function(d, i) { return d.id == focusedCountry.id ? focused = d : false; });
//svg.selectAll("circle").attr("d", data)
//.classed("focused", function(d, i) { return d.id == focusedCountry.id ? focused = d : false; });
};
})
})();
});
function country(cnt, sel) {
for(var i = 0, l = cnt.length; i < l; i++) {
if(cnt[i].id == sel.value) {return cnt[i];}
}
};
};
</script>
Please help.
Thank you in advance

Here is an option, using point geometries:
.enter().append('path')
.attr('class', 'circle_el')
.attr('fill', function(d) {return d.fill; })
.datum(function(d) {
return {type: 'Point', coordinates: [d.lon, d.lat], radius: some_radius};
})
.attr('d', path);
This is cool because you will update the circles simultaneously with a path redraw. And in addition it will account for the projection as a sphere, not showing circles that should be on the non-visible side of the sphere. I got the idea from this post by Jason Davies.

d3 stacked bar mouse over whole bar

I have created a stacked bar graph using a tutorial. The stack is created with the following:
var layers = d3.layout.stack()(["passed", "failed", "skipped"].map(function(cause){
return data.map(function(d){
return {x: d.UP, y: +d[cause]};
});
}));
When I hover my mouse over a stack, I want the whole stack to be marked (e.g. stronger border line).
I am currently using:
var barMouseOverFunction = function(d, i) {
var bar = d3.select(this);
bar.attr("stroke", "black" );
However this only changes for the current stack. Any ideas of how to get all the bars in the stack?
EDIT FULLCODE:
d3.json('db/data.php', function(data) {
var layers = d3.layout.stack()(["passed", "failed", "skipped"].map(function(cause){
return data.map(function(d){
return {x: d.UP, y: +d[cause]};
});
}));
var n = 3, // number of layers
stack = d3.layout.stack(),
yGroupMax = d3.max(layers, function(layer) { return d3.max(layer, function(d) { return d.y; }); }),
yStackMax = d3.max(layers, function(layer) { return d3.max(layer, function(d) { return d.y0 + d.y; }); });
var x = d3.scale.ordinal()
.domain(data.map(function(d){return d.UP;}))
.rangeRoundBands([0, width], .4);
var y = d3.scale.linear()
.domain([0, yStackMax])
.range([height, 0]);
var color = d3.scale.ordinal()
.range(["#6ad46a", "#ed2828", "#fae650"]);
var xAxis = d3.svg.axis()
.scale(x)
.tickSize(0)
.tickPadding(6)
.orient("bottom");
// Grid lines
var gridcontainer = svg.append('g');
gridcontainer.selectAll("line").data(y.ticks(10)).enter().append("line")
.attr("x1", 0)
.attr("x2", width)
.attr("y1", y)
.attr("y2", y)
.style("stroke", "#87cbff")
.style("stroke-width", .3);
var layer = svg.selectAll(".layer")
.data(layers)
.enter().append("g")
.attr("class", "layer")
.style("fill", function(d, i) { return color(i); })
.style("stroke", function(d, i){return d3.rgb(color(i)).darker();});
var timeformatter = d3.time.format("%b %e %Y %x%p");
// On mouseover display test case information
var barMouseOverFunction = function(d, i) {
var bar = d3.select(this);
bar.attr("stroke", "black" );
var dataItem = data[i];
}
var barMouseOutFunction = function() {
var bar = d3.select(this);
bar.attr("stroke", function(d){
return StatusColor(d.result);
});
d3.select("p").text("");
}
var rect = layer.selectAll("rect")
.data(function(d) { return d; })
.enter().append("rect")
.attr("x", function(d) { return x(d.x); })
.attr("y", height)
.attr("width", x.rangeBand())
.attr("height", 0)
.attr("rx", 0.5)
.attr("ry", 0.5)
.on("mouseover", barMouseOverFunction)
.on("mouseout", barMouseOutFunction);

The easiest way to do this is probably to assign a separate class to the bars for a particular stack and then select based on that, i.e. something like
var rect = layer.selectAll("rect")
.data(function(d) { return d; })
.enter().append("rect")
.attr("class", function(d, i, j) { return "stack" + j; })
...
var barMouseOverFunction = function(d, i, j) {
d3.selectAll("rect.stack" + j).attr("stroke", "black");
var dataItem = data[i];
}