Develop Reference

D3 Grouped Bar Chart From Arrays

I'm really having trouble with D3 and need some help changing my existing barchart to be a grouped barchart The barchart is being used within a tooltip and currently looks like:
Each colour represents a sector of industry (pink = retail, teal = groceries...etc).
I need to change the bar chart so that it compares the percentage change in each industry with the world average percentage change in this industry.
At the moment the bar chart is being created from an array of data. I also have an array with the world percentage values.
So imagine:
countryData = [10,-20,-30,-63,-23,20],
worldData = [23,-40,-23,-42,-23,40]
Where index 0 = retail sector, index 1 = grocery sector, etc.
I need to plot a grouped barchart comparing each sector to the world average (show the world average in red). This is a bit tricky to explain so I drew it for you (...excuse the shoddy drawing).
Please can someone help me change my existing tooltip?
Here's the current code. If you want to simulate the data values changing.
If you want to scrap my existing code that's fine.
.on('mouseover', ({ properties }) => {
// get county data
const mobilityData = covid.data[properties[key]] || {};
const {
retailAverage,
groceryAverage,
parksAverage,
transitAverage,
workplaceAverage,
residentialAverage,
} = getAverage(covid1);
let avgArray = [retailAverage, groceryAverage, parksAverage, transitAverage, workplaceAverage, retailAverage];
let categoriesNames = ["Retail", "Grocery", "Parks", "Transit", "Workplaces", "Residential"];
// create tooltip
div = d3.select('body')
.append('div')
.attr('class', 'tooltip')
.style('opacity', 0);
div.html(properties[key]);
div.transition()
.duration(200)
.style('opacity', 0.9);
// calculate bar graph data for tooltip
const barData = [];
Object.keys(mobilityData).forEach((industry) => {
const stringMinusPercentage = mobilityData[industry].slice(0, -1);
barData.push(+stringMinusPercentage); // changing it to an integer value, from string
});
//combine the two lists for the combined bar graph
var combinedList = [];
for(var i = 0; i < barData.length; i++) {
const stringMinusPercentage2 = +(avgArray[i].slice(0, -1));
const object = {category: categoriesNames[i], country: barData[i], world: stringMinusPercentage2}
combinedList.push(object); //Push object into list
}
console.log(combinedList);
// barData = barData.sort(function (a, b) { return a - b; });
// sort into ascending ^ keeping this in case we need it later
const height2 = 220;
const width2 = 250;
const margin = {
left: 50, right: 10, top: 20, bottom: 15,
};
// create bar chart svg
const svgA = div.append('svg')
.attr('height', height2)
.attr('width', width2)
.style('border', '1px solid')
.append('g')
// apply the margins:
.attr('transform', `translate(${[`${margin.left},${margin.top}`]})`);
const barWidth = 30; // Width of the bars
// plot area is height - vertical margins.
const chartHeight = height2 - margin.top - margin.left;
// set the scale:
const yScale = d3.scaleLinear()
.domain([-100, 100])
.range([chartHeight, 0]);
// draw some rectangles:
svgA
.selectAll('rect')
.data(barData)
.enter()
.append('rect')
.attr('x', (d, i) => i * barWidth)
.attr('y', (d) => {
if (d < 0) {
return yScale(0); // if the value is under zero, the top of the bar is at yScale(0);
}
return yScale(d); // otherwise the rectangle top is above yScale(0) at yScale(d);
})
.attr('height', (d) => Math.abs(yScale(0) - yScale(d))) // the height of the rectangle is the difference between the scale value and yScale(0);
.attr('width', barWidth)
.style('fill', (d, i) => colours[i % 6]) // colour the bars depending on index
.style('stroke', 'black')
.style('stroke-width', '1px');
// Labelling the Y axis
const yAxis = d3.axisLeft(yScale);
svgA.append('text')
.attr('class', 'y label')
.attr('text-anchor', 'end')
.attr('x', -15)
.attr('y', -25)
.attr('dy', '-.75em')
.attr('transform', 'rotate(-90)')
.text('Percentage Change (%)');
svgA.append('g')
.call(yAxis);
})
.on('mouseout', () => {
div.style('opacity', 0);
div.remove();
})
.on('mousemove', () => div
.style('top', `${d3.event.pageY - 140}px`)
.style('left', `${d3.event.pageX + 15}px`));
svg.append('g')
.attr('transform', 'translate(25,25)')
.call(colorLegend, {
colorScale,
circleRadius: 10,
spacing: 30,
textOffset: 20,
});
};
drawMap(svg1, geoJson1, geoPath1, covid1, key1, 'impact1');
drawMap(svg2, geoJson2, geoPath2, covid2, key2, 'impact2');
};

In short I would suggest you to use two Band Scales for x axis. I've attached a code snippet showing the solution.
Enjoy ;)
//Assuming the following data final format
var finalData = [
{
"groupKey": "Retail",
"sectorValue": 70,
"worldValue": 60
},
{
"groupKey": "Grocery",
"sectorValue": 90,
"worldValue": 90
},
{
"groupKey": "other",
"sectorValue": -20,
"worldValue": 30
}
];
var colorRange = d3.scaleOrdinal().range(["#00BCD4", "#FFC400", "#ECEFF1"]);
var subGroupKeys = ["sectorValue", "worldValue"];
var svg = d3.select("svg");
var margin = {top: 20, right: 20, bottom: 30, left: 40};
var width = +svg.attr("width") - margin.left - margin.right;
var height = +svg.attr("height") - margin.top - margin.bottom;
var container = svg.append("g").attr("transform", "translate(" + margin.left + "," + margin.top + ")");
// The scale spacing the groups, your "sectors":
var x0 = d3.scaleBand()
.domain(finalData.map(d => d.groupKey))
.rangeRound([0, width])
.paddingInner(0.1);
// The scale for spacing each group's bar, your "sector bar":
var x1 = d3.scaleBand()
.domain(subGroupKeys)
.rangeRound([0, x0.bandwidth()])
.padding(0.05);
var yScale = d3.scaleLinear()
.domain([-100, 100])
.rangeRound([height, 0]);
//and then you will need to append both, groups and bars
var groups = container.append('g')
.selectAll('g')
.data(finalData, d => d.groupKey)
.join("g")
.attr("transform", (d) => "translate(" + x0(d.groupKey) + ",0)");
//define groups bars, one per sub group
var bars = groups
.selectAll("rect")
.data(d => subGroupKeys.map(key => ({ key, value: d[key], groupKey: d.groupKey })), (d) => "" + d.groupKey + "_" + d.key)
.join("rect")
.attr("fill", d => colorRange(d.key))
.attr("x", d => x1(d.key))
.attr("width", (d) => x1.bandwidth())
.attr('y', (d) => Math.min(yScale(0), yScale(d.value)))
.attr('height', (d) => Math.abs(yScale(0) - yScale(d.value)));
//append x axis
container.append("g")
.attr("class", "axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x0));
//append y axis
container.append("g")
.attr("class", "y axis")
.call(d3.axisLeft(yScale))
.append("text")
.attr("x", 2)
.attr("y", yScale(yScale.ticks().pop()) + 0.5)
.attr("dy", "0.32em")
.attr("fill", "#000")
.attr("font-weight", "bold")
.attr("text-anchor", "start")
.text("Values");
<script src="https://d3js.org/d3.v7.min.js"></script>
<svg width="600" height="400"></svg>

D3 Charting Tool: How to add label at right of target line (additional horizontal line) in column chart

I have drawn the following chart with D3 Charting tool v4. I have attached the full code at the bottom of this post.
The red line is the target goal to be achieved. The following code block is drawing this line:
var targetGoalArr = [7];
svg.selectAll(".targetgoal")
.data(targetGoalArr)
.enter().append("line")
.attr("class", "targetgoal")
.attr("x1", 0)
.attr("x2", width)
.attr("y1", y)
.attr("y2", y)
.style("stroke", "#cc0000");
Now I need to label this line with the text Growth Target (7) to the right of it and in two lines. The label has to be broken in two lines as well!
The following screenshot shows the desired output.
How can I achieve the above?
One more thing I am not able to draw is the Y-Axis baseline. In my chart (with red line) I am creating the horizontal lines using a custom tick array. Here is the code:
function draw_yAxis_gridlines() {
return d3.axisLeft(y)
.tickValues(yTicks);
}
svg.append("g")
.attr("class", "grid axis")
.call(draw_yAxis_gridlines()
.tickSize(-width)
);
However, if I do not use custom ticks for Y-Axis, the baseline appears but I am missing the horizontal grid lines. I have to display both at the same time.
Here is my full code:
public function evd_unitary_growth_plan_chart( $data_str ){
ob_start(); ?>
<style> /* set the CSS */
.line {
fill: none;
stroke: steelblue;
stroke-width: 2px;
}
.grid line {
stroke: lightgrey;
stroke-opacity: 0.5;
shape-rendering: crispEdges;
}
.grid path {
stroke-width: 0;
}
.axis {
font-size: 13px;
font-family: 'Roboto';
color: #808888;
}
</style>
<script type="text/javascript">
var h = 300;
var w = 750;
var barPadding = 2;
function barColor(data_month, current_month) {
if( parseInt(data_month) >= current_month)
return "#008600";
else
return "#c4c4c4";
}
// set the dimensions and margins of the graph
var margin = {top: 30, right: 20, bottom: 30, left: 40},
width = w - margin.left - margin.right,
height = h - margin.top - margin.bottom;
var data = <?php echo $data_str ?>;
// set the ranges
var x = d3.scaleBand().range([0, width]).padding(0.2);
var y = d3.scaleLinear().range([height, 0]);
var svg = d3.select("#ecbg_unitary").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
// Scale the range of the data in the domains
x.domain(data.map(function(d) { return d.month; }));
var y_domain_upperBound = d3.max(data, function(d) { return d.points; });
y_domain_upperBound = Math.round(y_domain_upperBound / 10) * 10 + 10;
y.domain([0, y_domain_upperBound]);
// Create Y-Axis tick array to draw grid lines
var yTicks = [];
var tickInterval = 5;
for(var i = 0; i <= y_domain_upperBound; i = i + tickInterval) {
yTicks.push(i);
}
console.log(yTicks);
// gridlines in y axis function
function draw_yAxis_gridlines() {
return d3.axisLeft(y)
.tickValues(yTicks);
}
// Reference line - The red line
var targetGoalArr = [7];
svg.selectAll(".targetgoal")
.data(targetGoalArr)
.enter().append("line")
.attr("class", "targetgoal")
.attr("x1", 0)
.attr("x2", width)
.attr("y1", y)
.attr("y2", y)
.style("stroke", "#cc0000");
// append the rectangles for the bar chart
svg.selectAll("rect")
.data(data)
.enter().append("rect")
.attr("x", function(d) {
return x(d.month);
})
.attr("width", x.bandwidth())
.attr("y", function(d) { return y(d.points); })
.attr("height", function(d) { return height - y(d.points); })
.attr("fill", function(d){return barColor(d.data_month_number, d.current_month_number)});
// column labels
svg.selectAll("text")
.data(data)
.enter()
.append("text")
.text(function(d) {
return d.points;
})
.attr("text-anchor", "middle")
.attr("x", function(d, i) {
return x(d.month) + x.bandwidth() / 2;
})
.attr("y", function(d) {
return y(d.points) - 10;
})
.attr("font-family", "Roboto")
.attr("font-size", "13px")
.attr("font-weight", "bold")
.attr("fill", "#606668");
// add the x Axis
svg.append("g")
.attr("class", "axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x));
// add the Y gridlines
svg.append("g")
.attr("class", "grid axis")
.call(draw_yAxis_gridlines()
.tickSize(-width)
);
</script>
<?php return ob_get_clean();
}

To add a label to your target line, you are best to create group (g) element, and then append a line and text element to it. The g element can be translated to the correct y position, so that the line and text can be positioned relatively to the g.
var targetGoalArr = [7];
var target = g.selectAll(".targetgoal")
.data(targetGoalArr)
.enter()
.append("g")
.attr("transform", function(d){
return "translate(0, " + y(d) +")"
})
target.append("line")
.attr("class", "targetgoal")
.attr("x1", 0)
.attr("x2", width)
.attr("y1", 0) //these can be omitted
.attr("y2", 0)
.style("stroke", "#cc0000");
target.append("text")
.text(function(d){ return "Target growth: " + d })
.attr("x", width)
.attr("y", "0.35em")

How to make a flat line in D3.js (version 3.x)

I have a graph which I can add a flat line with the following:
svg.append("line") // attach a line
.style("stroke", "black")
.attr("x", 60) // x position of the first end of the line
.attr("y1", 60) // y position of the first end of the line
.attr("x2", 60) // x position of the second end of the line
.attr("y2", 60);
However, this only crosses 1/3 of the graph. How do I add a flat line that will always go as far as the graph is long? Thanks

I assume you are using scales, at least for your date axis, so I would do something like this:
// Scales
const xScale = d3.scaleTime()
.range([0, 400])
.domain(d3.extent(data, d => new Date(d.date)))
const yScale = d3.scaleLinear()
.range([600, 0])
.domain([0, 100])
svg.append("line")
.style("stroke", "black")
.attr('x1', 0)
.attr('x2', 400)
.attr('y1', yScale(60))
.attr('y2', yScale(60))

You can add line to complete graph by using range function that you generated for making line chart.
line_straight = svg.append("line") // attach a line
.style("stroke", "black")
.attr("x", 0) // x position of the first end of the line
.attr("y1", yScale(0.8)) // y position of the first end of the line
.attr("x2", xScale(n-1)) // x position of the second end of the line
.attr("y2", yScale(0.8));
Below i am attaching my code. Here is the jsfiddle to the code. https://jsfiddle.net/nmks14ub/1/
// 2. Use the margin convention practice
var margin = {top: 50, right: 50, bottom: 50, left: 50}
, width = window.innerWidth - margin.left - margin.right // Use the window's width
, height = window.innerHeight - margin.top - margin.bottom; // Use the window's height
// The number of datapoints
var n = 21;
// 5. X scale will use the index of our data
var xScale = d3.scaleLinear()
.domain([0, n-1]) // input
.range([0, width]); // output
// 6. Y scale will use the randomly generate number
var yScale = d3.scaleLinear()
.domain([0, 1]) // input
.range([height, 0]); // output
// 7. d3's line generator
var line = d3.line()
.x(function(d, i) { return xScale(i); }) // set the x values for the line generator
.y(function(d) { return yScale(d.y); }) // set the y values for the line generator
.curve(d3.curveLinear) // apply smoothing to the line
// 8. An array of objects of length N. Each object has key -> value pair, the key being "y" and the value is a random number
var dataset = d3.range(n).map(function(d) { return {"y": d3.randomUniform(1)() } })
// 1. Add the SVG to the page and employ #2
var svg = d3.select("body").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
// 3. Call the x axis in a group tag
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(xScale)); // Create an axis component with d3.axisBottom
line_straight = svg.append("line") // attach a line
.style("stroke", "black")
.attr("x", 0) // x position of the first end of the line
.attr("y1", yScale(0.8)) // y position of the first end of the line
.attr("x2", xScale(n-1)) // x position of the second end of the line
.attr("y2", yScale(0.8));
// 4. Call the y axis in a group tag
svg.append("g")
.attr("class", "y axis")
.call(d3.axisLeft(yScale)); // Create an axis component with d3.axisLeft
// 9. Append the path, bind the data, and call the line generator
svg.append("path")
.datum(dataset) // 10. Binds data to the line
.attr("class", "line") // Assign a class for styling
.attr("d", line); // 11. Calls the line generator
.line {
fill: none;
stroke: #ffab00;
stroke-width: 3;
}
.overlay {
fill: none;
pointer-events: all;
}
/* Style the dots by assigning a fill and stroke */
.dot {
fill: #ffab00;
stroke: #fff;
}
.focus circle {
fill: none;
stroke: steelblue;
}
<!DOCTYPE html>
<meta charset="utf-8">
<body>
</body>
<!-- Load in the d3 library -->
<script src="https://d3js.org/d3.v5.min.js"></script>

border for d3 stack bar chart on selection

Trying to implement border for selected bar in d3 stack bar chart. Here the first bar's top border goes behind second bar a little bit. How to avoid this?
var svg, height, width, margin, parentWidth, parentHeight;
// container size
parentWidth = 700;
parentHeight = 500;
margin = {top: 50, right: 20, bottom: 35, left: 30};
width = parentWidth - margin.left - margin.right;
height = parentHeight - margin.top - margin.bottom;
var selectedSection = window.sessionStorage.getItem('selectedSection');
// data
var dataset = [{"label":"DEC","Set Up":{"count":12,"id":1,"label":"Set Up","year":"2016","graphType":"setup"},"Not Set Up":{"count":12,"id":0,"label":"Not Set Up","year":"2016","graphType":"setup"}},{"label":"JAN","Set Up":{"count":6,"id":1,"label":"Set Up","year":"2017","graphType":"setup"},"Not Set Up":{"count":21,"id":0,"label":"Not Set Up","year":"2017","graphType":"setup"}},{"label":"FEB","Set Up":{"count":1,"id":1,"label":"Set Up","year":"2017","graphType":"setup"},"Not Set Up":{"count":2,"id":0,"label":"Not Set Up","year":"2017","graphType":"setup"}},{"label":"MAR","Set Up":{"count":0,"id":1,"label":"Set Up","year":"2017","graphType":"setup"},"Not Set Up":{"count":0,"id":0,"label":"Not Set Up","year":"2017","graphType":"setup"}},{"label":"APR","Set Up":{"count":0,"id":1,"label":"Set Up","year":"2017","graphType":"setup"},"Not Set Up":{"count":0,"id":0,"label":"Not Set Up","year":"2017","graphType":"setup"}}];
// x cord
var x = d3.scale.ordinal()
.rangeRoundBands([0, width], 0.2);
// color helper
var colorRange = d3.scale.category20();
var color = d3.scale.ordinal()
.range(colorRange.range());
// x axis
var xAxis = d3.svg.axis()
.scale(x)
.orient('bottom');
var colors = ['#50BEE9', '#30738C'];
// Set SVG
svg = d3.select('#chart')
.append('svg')
.attr('width', width + margin.left + margin.right)
.attr('height', height + margin.top + margin.bottom )
.attr('class', 'setup')
.append('g')
.attr('transform', 'translate(' + margin.left + ',' + margin.top + ')');
color.domain(d3.keys(dataset[0]).filter(function(key) { return key !== 'label'; }));
dataset.forEach(function(d) {
var y0 = 0;
d.values = color.domain().map(function(name) {
return {
name: name,
y0: y0,
y1: y0 += +d[name].count,
patientStatus:d[name].id,
graphType:d[name].graphType,
fromDate:{
month:d.label,
year:d[name].year
},
toDate:{
month:d.label,
year:d[name].year
}
};
});
d.total = d.values[d.values.length - 1].y1;
});
var y = d3.scale.linear()
.domain([0, d3.max(dataset, function(d) {
return d.total;
})])
.range([height, 0]);
var ticks = y.ticks(),
lastTick = ticks[ticks.length-1];
var newLastTick = lastTick + (ticks[1] - ticks[0]);
if (lastTick<y.domain()[1]){
ticks.push(lastTick + (ticks[1] - ticks[0]));
}
// adjust domain for further value
y.domain([y.domain()[0], newLastTick]);
// y axis
var yAxis = d3.svg.axis()
.scale(y)
.orient('left')
.tickSize(-width, 0, 0)
.tickFormat(d3.format('d'))
.tickValues(ticks);
x.domain(dataset.map(function(d) { return d.label; }));
y.domain([0, d3.max(dataset, function(d) { return d.total; })]);
svg.append('g')
.attr('class', 'x axis')
.attr('transform', 'translate(0,' + height + ')')
.call(xAxis);
svg.append('g')
.attr('class', 'y axis')
.call(yAxis);
var bar = svg.selectAll('.label')
.data(dataset)
.enter().append('g')
.attr('class', 'g')
.attr('id', function(d, i) {
return i;
})
.attr('transform', function(d) { return 'translate(' + x(d.label) + ',0)'; });
var barEnter = bar.selectAll('rect')
.data(function(d) { return d.values; })
.enter();
barEnter.append('rect')
.attr('width', x.rangeBand())
.attr('y', function(d) {
return y(d.y1);
})
.attr('class', function(d, i){
return 'bar';
})
.attr('height', function(d) { return y(d.y0) - y(d.y1); })
.style('fill', function(d,i) { return colors[i]; })
.on('click', function(d, i) {
d3.selectAll('.bar').classed('selected', false);
d3.select(this)
.classed('bar selected', true);
});
barEnter.append('text')
.text(function(d) {
var calcH = y(d.y0) - y(d.y1);
var inText = (d.y1-d.y0);
if(calcH >= 20) {
return inText;
} else {
return '';
}
})
.attr('class','inner-text')
.attr('y', function(d) { return y(d.y1)+(y(d.y0) - y(d.y1))/2 + 5; })
.attr('x', function(){
return (x.rangeBand()/2) - 10;
});
svg
.select('.y')
.selectAll('.tick')
.filter(function (d) {
return d % 1 !== 0;
})
.style('display','none');
svg
.select('.y')
.selectAll('.tick')
.filter(function (d) {
return d === 0;
})
.select('text')
.style('display','none');
JSFiddle
JSFiddle with d3 v4

In a SVG, just like a real painter putting ink to a white canvas, the element that is painted last stays on top.
Right now, the behaviour you're seeing is the expected one, because each stacked bar (rectangle) is in a different <g> element, and the groups, of course, have a given order in the SVG structure.
The solution involves just one line:
d3.select(this.parentNode).raise();
What this line does is selecting the group of the clicked rectangle and raising it (that is, moving it down in the DOM tree), so that group will be on top of all others. According to the API, raise():
Re-inserts each selected element, in order, as the last child of its parent. (emphasis mine)
"Moving down", "be on top" and "be the last child" may be a bit confusing and seem contradictory, but here is the explanation. Given this SVG structure:
<svg>
<foo></foo>
<bar></bar>
<baz></baz>
</svg>
<baz>, being the last element, is the one painted last, and it is the element visually on the top in the SVG. So, raising an element means moving it down in the SVG tree structure, but moving it up visually speaking.
Here is your updated fiddle: https://jsfiddle.net/86Lgaupt/
PS: I increased the stroke-width just to make visibly clear that the clicked rectangle is now on top.

Tag:
<div id='stacked-bar'></div>
Script:
var initStackedBarChart = {
draw: function(config) {
me = this,
domEle = config.element,
stackKey = config.key,
data = config.data,
margin = {top: 20, right: 20, bottom: 30, left: 50},
parseDate = d3.timeParse("%m/%Y"),
width = 550 - margin.left - margin.right,
height = 400 - margin.top - margin.bottom,
xScale = d3.scaleBand().range([0, width]).padding(0.1),
yScale = d3.scaleLinear().range([height, 0]),
color = d3.scaleOrdinal(d3.schemeCategory20),
xAxis = d3.axisBottom(xScale).tickFormat(d3.timeFormat("%b")),
yAxis = d3.axisLeft(yScale),
svg = d3.select("#"+domEle).append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top+10 + margin.bottom+10)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var stack = d3.stack()
.keys(stackKey)
.order(d3.stackOrderNone)
.offset(d3.stackOffsetNone);
var layers= stack(data);
data.sort(function(a, b) { return b.total - a.total; });
xScale.domain(data.map(function(d) { return parseDate(d.date); }));
yScale.domain([0, d3.max(layers[layers.length - 1], function(d) { return d[0] + d[1]; }) ]).nice();
var layer = svg.selectAll(".layer")
.data(layers)
.enter().append("g")
.attr("class", "layer")
.style("fill", function(d, i) { return color(i); });
layer.selectAll("rect")
.data(function(d) { return d; })
.enter().append("rect")
.attr('class', 'bar')
.attr("x", function(d) { return xScale(parseDate(d.data.date)); })
.attr("y", function(d) { return yScale(d[1]); })
.attr("height", function(d) { return yScale(d[0]) - yScale(d[1]) -1; })
.attr("width", xScale.bandwidth())
.on('click', function(d, i) {
d3.selectAll('.bar').classed('selected', false);
d3.select(this).classed('selected', true);
});
svg.append("g")
.attr("class", "axis axis--x")
.attr("transform", "translate(0," + (height+5) + ")")
.call(xAxis);
svg.append("g")
.attr("class", "axis axis--y")
.attr("transform", "translate(0,0)")
.call(yAxis);
}
}
var data = [
{"date":"4/1854","total":45,"disease":12,"wounds":14,"other":25},
{"date":"5/1854","total":23,"disease":12,"wounds":0,"other":9},
{"date":"6/1854","total":38,"disease":11,"wounds":0,"other":6},
{"date":"7/1854","total":26,"disease":11,"wounds":8,"other":7}
];
var key = ["wounds", "other", "disease"];
initStackedBarChart.draw({
data: data,
key: key,
element: 'stacked-bar'
});
Css:
.axis text {
font: 10px sans-serif;
}
.axis line,
.axis path {
fill: none;
stroke: #000;
shape-rendering: crispEdges;
}
.axis--x path {
display: none;
}
.path-line {
fill: none;
stroke: yellow;
stroke-width: 1.5px;
}
svg {
background: #f0f0f0;
}
.selected{
stroke:#333;
stroke-width:2;
}

Multiples with x/y axis and mouseover example - line path shows wrong values

I am trying to combine severeal D3.js examples based on example. I managed to get mouseover for each multiples chart in part working (values are not displayed at mouse pointer yet but via console.log). By checking those values I realized that my line paths at the upper two charts are off in relation to the Y-Axis, also causing the mouseover focus to be in the wrong place. I am new to D3, so I am still having trouble to pin down the problem beeing caused by domain/scale/axis etc. You can see the example here
This is my code:
<!DOCTYPE html>
<meta charset="utf-8">
<style>
body {
font: 10px sans-serif;
margin: 0;
}
.axis path,
.axis line {
fill: none;
stroke: #000;
//shape-rendering: crispEdges;
}
.line {
fill: none;
stroke: steelblue;
stroke-width: 1.5px;
}
.area {
//fill: #e7e7e7;
fill: transparent;
}
.overlay {
fill: none;
pointer-events: all;
}
.focus circle {
fill: none;
stroke: steelblue;
}
</style>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
<script>
var margin = {top: 8, right: 10, bottom: 20, left: 30},
width = 960 - margin.left - margin.right,
height = 138 - margin.top - margin.bottom;
var parseDate = d3.time.format("%b %Y").parse,
bisectDate = d3.bisector(function(d) { return d.date; }).left,
formatValue = d3.format(",.2f"),
formatCurrency = function(d) { return formatValue(d); };
var x = d3.time.scale()
.range([0, width]);
var y = d3.scale.linear()
.range([height, 0]);
var area = d3.svg.area()
.x(function(d) { return x(d.date); })
.y0(height)
.y1(function(d) { return y(d.price); });
var line = d3.svg.line()
.x(function(d) { return x(d.date); })
.y(function(d) { return y(d.price); });
var xAxis = d3.svg.axis()
.scale(x) // x is the d3.time.scale()
.orient("bottom") // the ticks go below the graph
.ticks(4); // specify the number of ticks
var yAxis = d3.svg.axis()
.scale(y)
.orient("left")
.ticks(4);
d3.csv("stocks_chart2.csv", type, function(error, data) {
// Nest data by symbol.
var symbols = d3.nest()
.key(function(d) { return d.symbol; })
.entries(data);
// Compute the maximum price per symbol, needed for the y-domain.
symbols.forEach(function(s) {
s.maxPrice = d3.max(s.values, function(d) { return d.price; });
});
// Compute the minimum and maximum date across symbols.
// We assume values are sorted by date.
x.domain([
d3.min(symbols, function(s) { return s.values[0].date; }),
d3.max(symbols, function(s) { return s.values[s.values.length - 1].date; })
]);
// Add an SVG element for each symbol, with the desired dimensions and margin.
var svg = d3.select("body").selectAll("svg")
.data(symbols)
.enter().append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
// Add the area path elements. Note: the y-domain is set per element.
svg.append("path")
.attr("class", "area")
.attr("d", function(d) { y.domain([0, d.maxPrice]); return area(d.values); });
// Add the line path elements. Note: the y-domain is set per element.
svg.append("path")
.attr("class", "line")
.attr("d", function(d) { y.domain([0, d.maxPrice]); return line(d.values); });
// Add a small label for the symbol name.
svg.append("text")
.attr("x", width - 6)
.attr("y", height - 6)
.style("text-anchor", "end")
.text(function(d) { return d.key; });
svg.append('g') // create a <g> element
.attr('class', 'x axis') // specify classes
.attr("transform", "translate(0," + height + ")")
.call(xAxis); // let the axis do its thing
svg.append("g")
.attr("class", "y axis")
.call(yAxis)
.append("text")
.attr("transform", "rotate(-90)")
.attr("y", 6)
.attr("dy", ".71em")
.style("text-anchor", "end")
.text("Value");
var focus = svg.append("g")
.attr("class", "focus")
.style("display", "none");
focus.append("circle")
.attr("r", 4.5);
focus.append("text")
.attr("x", 9)
.attr("dy", ".35em");
svg.append("rect")
.attr("class", "overlay")
.attr("width", width)
.attr("height", height)
.on("mouseover", function() { focus.style("display", null); })
.on("mouseout", function() { focus.style("display", "none"); })
.on("mousemove", mousemove);
function mousemove() {
var date, index;
date = x.invert(d3.mouse(this)[0]);
index = 0;
var focus = svg.selectAll(".focus");
focus.attr("transform", function(d) {
index = bisectDate(d.values, date, 0, d.values.length - 1);
console.log(index, d.values[index].symbol, d.values[index].date, d.values[index].price);
return "translate(" + x(d.values[index].date) + "," + y(d.values[index].price) + ")"
});
focus.selectAll("text", function(d) {
return formatCurrency(d.values[index].price);
});
}
});
function type(d) {
d.price = +d.price;
d.date = parseDate(d.date);
return d;
}
</script>
How do I assign the correct Y-Axis to each individual multiples chart causing the line path and mouseover values to be at the correct position? Any help would be greatly appreciated! Thank you!

This is an interesting problem. The example you link to uses a single y scale and yAxis for all 4 sub-plots. In your situation, though, your data has a very different domain for each sub-plot and when you add the dynamic mouse over a shared scale just won't work. So, my solution would be to create a different y scale and yAxis for each subplot.
...
// variable to hold our scales
var ys = {};
var area = d3.svg.area()
.x(function(d) {
return x(d.date);
})
.y0(height)
.y1(function(d) {
return ys[d.symbol](d.price); //<-- call the y function matched to our symbol
});
var line = d3.svg.line()
.x(function(d) {
return x(d.date);
})
.y(function(d, i) {
return ys[d.symbol](d.price); //<-- call the y scale function matched to our symbol
});
...
// for each symbol create our scale
symbols.forEach(function(s) {
var maxPrice = d3.max(s.values, function(d) {
return d.price;
});
ys[s.key] = d3.scale.linear() //<-- create a scale for each "symbol" (ie Sensor 1, etc...)
.range([height, 0])
.domain([0, maxPrice]);
});
...
// build 4 y axis
var axisGs = svg.append("g"); //<-- create a collection of axisGs
axisGs
.attr("class", "y axis")
.append("text")
.attr("transform", "rotate(-90)")
.attr("y", 6)
.attr("dy", ".71em")
.style("text-anchor", "end")
.text("Value");
axisGs.each(function(d, i) { //<-- for each axisG create an axis with it's scale
var self = d3.select(this);
self.call(
d3.svg.axis()
.scale(ys[d.key])
.orient("left")
.ticks(4)
);
});
...
// adjust mouseover to use appropriate scale
focus.attr("transform", function(d) {
index = bisectDate(d.values, date, 0, d.values.length - 1);
console.log(index, d.values[index].symbol, d.values[index].date, d.values[index].price);
return "translate(" + x(d.values[index].date) + "," + ys[d.key](d.values[index].price) + ")"; //<-- finally in our mouse move use the appropriate scale
});
Fully working code here.

As far as best practices are concerned when you are dealing with n number of datasets you have to go for n number of y scales and their corresponding y axis. It is good for seperation of concern and keeps the visulization intact. here you can see the example.
http://grafitome.github.io/advanced-charts.html#(first chart)