Zero tick vertically centered on axis when all values are 0 - d3.js

I've noticed a change in behavior when updating from d3 version 4 to version 5. In v4, when a dataset contains all zero values for the y-axis, the "0" tick is correctly aligned to the bottom of the chart.
<head>
<!-- load the d3.js library -->
<script src="https://d3js.org/d3.v4.min.js"></script>
<style>
.line {
fill: none;
stroke: steelblue;
stroke-width: 2px;
}
</style>
</head>
<script>
var margin = {
top: 50,
right: 50,
bottom: 50,
left: 50
},
width = window.innerWidth - margin.left - margin.right,
height = window.innerHeight - margin.top - margin.bottom;
var n = 21;
// 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)() } })
var dataset = d3.range(n).map(function(d) {
return {
"y": 0
}
})
var xScale = d3.scaleLinear()
.domain([0, n - 1])
.range([0, width]);
var yScale = d3.scaleLinear()
.domain([0, d3.max(dataset, d => d.y)])
.range([height, 0]);
var line = d3.line()
.x(function(d, i) {
return xScale(i);
})
.y(function(d) {
return yScale(d.y);
})
.curve(d3.curveMonotoneX)
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 + ")");
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(xScale));
svg.append("g")
.attr("class", "y axis")
.call(d3.axisLeft(yScale));
svg.append("path")
.datum(dataset)
.attr("class", "line")
.attr("d", line);
</script>
For my use case, this is the expected behavior.
In v5, under the same conditions, the "0" is aligned to the center of the y-axis.
<head>
<!-- load the d3.js library -->
<script src="https://d3js.org/d3.v5.min.js"></script>
<style>
.line {
fill: none;
stroke: steelblue;
stroke-width: 2px;
}
</style>
</head>
<script>
var margin = {top: 50, right: 50, bottom: 50, left: 50}
, width = window.innerWidth - margin.left - margin.right
, height = window.innerHeight - margin.top - margin.bottom;
var n = 21;
// 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)() } })
var dataset = d3.range(n).map(function(d) { return {"y": 0 } })
var xScale = d3.scaleLinear()
.domain([0, n-1])
.range([0, width]);
var yScale = d3.scaleLinear()
.domain([0, d3.max(dataset, d => d.y)])
.range([height, 0]);
var line = d3.line()
.x(function(d, i) { return xScale(i); })
.y(function(d) { return yScale(d.y); })
.curve(d3.curveMonotoneX)
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 + ")");
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(xScale));
svg.append("g")
.attr("class", "y axis")
.call(d3.axisLeft(yScale));
svg.append("path")
.datum(dataset)
.attr("class", "line")
.attr("d", line);
</script>
The only difference between the two examples is the version of d3 that is loaded.
Is there any way that I can keep the same behavior exhibited in v4 in the current version (v5) of d3?

This is not a difference between D3 v4 and v5. Actually, this change was introduced in D3 v5.8.
Have a look here, this is your code using D3 v5.7:
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.js"></script>
<style>
.line {
fill: none;
stroke: steelblue;
stroke-width: 2px;
}
</style>
</head>
<script>
var margin = {
top: 50,
right: 50,
bottom: 50,
left: 50
},
width = window.innerWidth - margin.left - margin.right,
height = window.innerHeight - margin.top - margin.bottom;
var n = 21;
// 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)() } })
var dataset = d3.range(n).map(function(d) {
return {
"y": 0
}
})
var xScale = d3.scaleLinear()
.domain([0, n - 1])
.range([0, width]);
var yScale = d3.scaleLinear()
.domain([0, d3.max(dataset, d => d.y)])
.range([height, 0]);
var line = d3.line()
.x(function(d, i) {
return xScale(i);
})
.y(function(d) {
return yScale(d.y);
})
.curve(d3.curveMonotoneX)
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 + ")");
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(xScale));
svg.append("g")
.attr("class", "y axis")
.call(d3.axisLeft(yScale));
svg.append("path")
.datum(dataset)
.attr("class", "line")
.attr("d", line);
</script>
Now the same code, using D3 v5.8:
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.8.0/d3.js"></script>
<style>
.line {
fill: none;
stroke: steelblue;
stroke-width: 2px;
}
</style>
</head>
<script>
var margin = {
top: 50,
right: 50,
bottom: 50,
left: 50
},
width = window.innerWidth - margin.left - margin.right,
height = window.innerHeight - margin.top - margin.bottom;
var n = 21;
// 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)() } })
var dataset = d3.range(n).map(function(d) {
return {
"y": 0
}
})
var xScale = d3.scaleLinear()
.domain([0, n - 1])
.range([0, width]);
var yScale = d3.scaleLinear()
.domain([0, d3.max(dataset, d => d.y)])
.range([height, 0]);
var line = d3.line()
.x(function(d, i) {
return xScale(i);
})
.y(function(d) {
return yScale(d.y);
})
.curve(d3.curveMonotoneX)
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 + ")");
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(xScale));
svg.append("g")
.attr("class", "y axis")
.call(d3.axisLeft(yScale));
svg.append("path")
.datum(dataset)
.attr("class", "line")
.attr("d", line);
</script>
The explanation can be found on the release notes for D3 v5.8:
D3-Scale:
For collapsed domains, use midpoint of domain or range rather than start. (emphases mine)
Therefore, I'm afraid there is nothing you can do, unless moving back to D3 v5.7 or lower.
In fact, D3 v5.8 is so different from v5.7 (and not backwards compatible, see the new scale constructors, for instance, or the new join method) that in my humble opinion it should have been named D3 v6.0 (of course, following the semantic versioning it was still named v5 because there were no breaking changes). There is arguably more differences from v5.7 to v5.8 than from v4 to v5.

In your definition of the yScale domain there is only one value (zero). Therefor, the value is correctly displayed in the middle of the axis.
You can fix that by adapting the domain but then you will get more ticks on the axis.
Only one example (you could add any other number):
var yScale = d3.scaleLinear()
.domain([0, d3.max(dataset, d => d.y)+1])
.range([height, 0]);

Encountered this same issue in d3 v7 - the workaround is setting a valid range like previously answered and conditionally display the tick marks and labels.
const height = *HEIGHT OF YOUR CHART*
const dataMax = Math.max(...*YOUR DATA*)
const dataMin = Math.min(...*YOUR DATA*)
const dataMinMaxZero = dataMax === 0 && dataMin === 0
const scaleMax = dataMinMaxZero ? 1 : dataMax;
const yScale = d3.scaleLinear()
.domain([dataMin, scaleMax])
.range([height, 0]);
const yAxis = d3.axisLeft(yScale)
d3.select("#yaxis").call(yAxis);
if (dataMinMaxZero) {
d3.select("#yaxis").selectAll(".tick").style("opacity", 0);
} else {
d3.select("#yaxis").selectAll(".tick").style("opacity", 1);
}

Related

String x ticks not scaling data in D3

`
var margin = {top: 50, right: 50, bottom: 50, left: 50}
, width = window.innerWidth - margin.left - margin.right
, height = window.innerHeight - margin.top - margin.bottom;
// n data points
var n = 7;
// X scale
var xScale = d3.scaleBand()
.domain(['A','B','C','D','F','E','Z']) // input
.range([0, width]); // output
// Y scale
var yScale = d3.scaleLinear()
.domain([0, 1])
.range([height, 0]);
var line = d3.line()
.x(function(d, i) { return xScale(i); })
.y(function(d) { return yScale(d.y); })
.curve(d3.curveMonotoneX)
var dataset = d3.range(n).map(function(d) { return {"y": d3.randomUniform(1)()} })
// SVGs
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 + ")");
svg.append("rect")
.attr("width", "100%")
.attr("height", "100%")
.attr("fill", "white");
svg.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
// x axis call
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(xScale));
// y axis call
svg.append("g")
.attr("class", "y axis")
.call(d3.axisLeft(yScale));
svg.append("path")
.datum(dataset)
.attr("class", "line")
.attr("d", line);
// 12. Appends a circle for each datapoint
svg.selectAll(".dot")
.data(dataset)
.enter().append("circle") // Uses the enter().append() method
.attr("class", "dot") // Assign a class for styling
.attr("cx", function(d, i) { return xScale(i) })
.attr("cy", function(d) { return yScale(d.y) })
.attr("r", 6);
svg.append("text")
.attr("class", "title")
.attr("x", width/2)
.attr("y", 0 - (margin.top / 2))
.attr("text-anchor", "middle")
.text("Testing");
/* 13. Basic Styling with CSS */
/* Style the lines by removing the fill and applying a stroke */
.line {
fill: none;
stroke: green;
stroke-width: 3;
}
/* Style the dots by assigning a fill and stroke */
.dot {
fill: red;
stroke: #fff;
}
<!DOCTYPE html>
<meta charset="utf-8">
<style type="text/css">
</style>
<!-- Body tag is where we will append our SVG and SVG objects-->
<body>
</body>
<!-- Load in the d3 library -->
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
</script>
I need for each data point to correspond to an (string) x-coordinate.
I am knew to d3 and I have yet to get accustomed to formatting axis.
I would also be great if anyone can point me out to how to add a tooltip. (Just an explanation)
Thank you everyone.
Not sure why it keeps saying your: "
It looks like your post is mostly code; please add some more details."
`
The scaleOrdinal is mapped to an array of alphabets but when you are calculating the cx you are mapping to an integer i. To resolve this:
Separate the labels as as array first:
var labels = ['A','B','C','D','F','E','Z'];
Then pass the labels to the domain:
// X scale
var xScale = d3.scaleBand()
.domain(labels) // input
.range([0, width]); // output
Finally, when you call calculate the cx, you need to send a value which was used in the domain. In your case since your domain is an array of alphabets you need to reparse the i to that particular alphabet. Hence you need to return xScale(labels[i]) as below:
svg.selectAll(".dot")
.data(dataset)
.enter().append("circle") // Uses the enter().append() method
.attr("class", "dot") // Assign a class for styling
.attr("cx", function(d, i) { return xScale(labels[i]) })
.attr("cy", function(d) { return yScale(d.y) })
.attr("r", 6);
Full working snippet below. Hope this helps.
var margin = {top: 50, right: 50, bottom: 50, left: 50}
, width = window.innerWidth - margin.left - margin.right
, height = window.innerHeight - margin.top - margin.bottom;
// n data points
var n = 7;
//labels
var labels = ['A','B','C','D','F','E','Z'];
// X scale
var xScale = d3.scaleBand()
.domain(labels) // input
.range([0, width]); // output
// Y scale
var yScale = d3.scaleLinear()
.domain([0, 1])
.range([height, 0]);
var line = d3.line()
.x(function(d, i) { return xScale(i); })
.y(function(d) { return yScale(d.y); })
.curve(d3.curveMonotoneX)
var dataset = d3.range(n).map(function(d) { return {"y": d3.randomUniform(1)()} })
// SVGs
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 + ")");
svg.append("rect")
.attr("width", "100%")
.attr("height", "100%")
.attr("fill", "white");
svg.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
// x axis call
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(xScale));
// y axis call
svg.append("g")
.attr("class", "y axis")
.call(d3.axisLeft(yScale));
svg.append("path")
.datum(dataset)
.attr("class", "line")
.attr("d", line);
// 12. Appends a circle for each datapoint
svg.selectAll(".dot")
.data(dataset)
.enter().append("circle") // Uses the enter().append() method
.attr("class", "dot") // Assign a class for styling
.attr("cx", function(d, i) { return xScale(labels[i]) })
.attr("cy", function(d) { return yScale(d.y) })
.attr("r", 6);
svg.append("text")
.attr("class", "title")
.attr("x", width/2)
.attr("y", 0 - (margin.top / 2))
.attr("text-anchor", "middle")
.text("Testing");
/* 13. Basic Styling with CSS */
/* Style the lines by removing the fill and applying a stroke */
.line {
fill: none;
stroke: green;
stroke-width: 3;
}
/* Style the dots by assigning a fill and stroke */
.dot {
fill: red;
stroke: #fff;
}
<!DOCTYPE html>
<meta charset="utf-8">
<style type="text/css">
</style>
<!-- Body tag is where we will append our SVG and SVG objects-->
<body>
</body>
<!-- Load in the d3 library -->
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
</script>
Updated Snippet with Lines:
var margin = {top: 50, right: 50, bottom: 50, left: 50}
, width = window.innerWidth - margin.left - margin.right
, height = window.innerHeight - margin.top - margin.bottom;
// n data points
var n = 7;
//labels
var labels = ['A','B','C','D','F','E','Z'];
// X scale
var xScale = d3.scaleBand()
.domain(labels) // input
.range([0, width]); // output
// Y scale
var yScale = d3.scaleLinear()
.domain([0, 1])
.range([height, 0]);
var line = d3.line()
.x(function(d, i) { return xScale(labels[i]); })
.y(function(d) { return yScale(d.y); })
.curve(d3.curveMonotoneX)
var dataset = d3.range(n).map(function(d) { return {"y": d3.randomUniform(1)()} })
// SVGs
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 + ")");
svg.append("rect")
.attr("width", "100%")
.attr("height", "100%")
.attr("fill", "white");
svg.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
// x axis call
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(xScale));
// y axis call
svg.append("g")
.attr("class", "y axis")
.call(d3.axisLeft(yScale));
svg.append("path")
.datum(dataset)
.attr("class", "line")
.attr("d", line);
// 12. Appends a circle for each datapoint
svg.selectAll(".dot")
.data(dataset)
.enter().append("circle") // Uses the enter().append() method
.attr("class", "dot") // Assign a class for styling
.attr("cx", function(d, i) { return xScale(labels[i]) })
.attr("cy", function(d) { return yScale(d.y) })
.attr("r", 6);
svg.append("text")
.attr("class", "title")
.attr("x", width/2)
.attr("y", 0 - (margin.top / 2))
.attr("text-anchor", "middle")
.text("Testing");
/* 13. Basic Styling with CSS */
/* Style the lines by removing the fill and applying a stroke */
.line {
fill: none;
stroke: green;
stroke-width: 3;
}
/* Style the dots by assigning a fill and stroke */
.dot {
fill: red;
stroke: #fff;
}
<!DOCTYPE html>
<meta charset="utf-8">
<style type="text/css">
</style>
<!-- Body tag is where we will append our SVG and SVG objects-->
<body>
</body>
<!-- Load in the d3 library -->
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
</script>

Access y value of a d3.line after interpolation [duplicate]

This question already has an answer here:
How do I return y coordinate of a path in d3.js?
(1 answer)
Closed 3 years ago.
I am drawing a simple line using the curveMonotoneX interpolation :
const line = d3
.line()
.x((_, i) => xScale(i))
.y(d => yScale(d))
.curve(d3.curveMonotoneX);
Besides that, I wanted to add points on the line where there is actual data. Because of the interpolation, the points I drawn were not exactly on the line so I switched to d3.curveLinear and my issues were gone.
However, I was wondering is there a ready-to-use method to access the y value of a line using the x value ?
This way, one could draw the points on the line regardless of the interpolation method.
Here's a quick example, wrapping the code here into a reusable function. It places a bunch of points on a fitted curve.
<!DOCTYPE html>
<meta charset="utf-8">
<style type="text/css">
.line {
fill: none;
stroke: orange;
stroke-width: 2;
}
.overlay {
fill: none;
pointer-events: all;
}
.dot {
fill: steelblue;
stroke: #fff;
}
</style>
<body>
<!-- Load in the d3 library -->
<script src="https://d3js.org/d3.v5.min.js"></script>
<script>
var margin = {
top: 50,
right: 50,
bottom: 50,
left: 50
},
width = window.innerWidth - margin.left - margin.right,
height = window.innerHeight - margin.top - margin.bottom;
var xScale = d3.scaleLinear()
.domain([0, 9])
.range([0, width]);
var yScale = d3.scaleLinear()
.domain([0, 10])
.range([height, 0]);
var line = d3.line()
.x(function(d, i) {
return xScale(i);
})
.y(function(d) {
return yScale(d);
})
.curve(d3.curveBasis);
var dataset = d3.range(10).map(function(d) {
return d3.randomUniform(1)() * 10;
})
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 + ")");
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(xScale));
svg.append("g")
.attr("class", "y axis")
.call(d3.axisLeft(yScale));
var path = svg.append("path")
.datum(dataset)
.attr("class", "line")
.attr("d", line);
svg.selectAll(".dot")
.data(d3.range(0, 9.5, 0.5))
.enter()
.append("circle")
.attr("cx", (d) => xScale(d))
.attr("cy", (d) => yValueForX(d))
.attr("r", 5)
.attr("class", "dot")
function yValueForX(xCor){
var x = xScale(xCor),
pathEl = path.node(),
pathLength = pathEl.getTotalLength();
var beginning = x, end = pathLength, target;
while (true) {
target = Math.floor((beginning + end) / 2);
pos = pathEl.getPointAtLength(target);
if ((target === end || target === beginning) && pos.x !== x) {
break;
}
if (pos.x > x) end = target;
else if (pos.x < x) beginning = target;
else break; //position found
}
return pos.y;
}
</script>
</body>

Formatting year in D3 V4 to remove commas

I am creating a line chart in D3 v4.
The x-axis is showing the year with commas like 1,998 and 1,999 instead of 1998 and 1999 etc. It is addig the thousand comma which is what I am trying to remove.
I am trying to remove the commas, but I have not been able to. tickformat is not working in v4.
<!DOCTYPE html>
<meta charset="utf-8">
<style> /* set the CSS */
.line {
fill: none;
stroke: steelblue;
stroke-width: 2px;
}
</style>
<body>
<!-- load the d3.js library -->
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
// set the dimensions and margins of the graph
var margin = {top: 50, right: 50, bottom: 100, left: 80},
width = 960 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
// set the ranges
var x = d3.scaleLinear().range([0, width]);
var y = d3.scaleLinear().range([height, 0]);
// define the line
var valueline = d3.line()
.x(function(d) { return x(d.Year); })
.y(function(d) { return y(d.Amount); });
// append the svg obgect to the body of the page
// appends a 'group' element to 'svg'
// moves the 'group' element to the top left margin
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 + ")");
// Get the data
d3.csv("australia.csv", function(error, data) {
if (error) throw error;
// format the data
data.forEach(function(d) {
d.Year = d.Year;
d.Amount = +d.Amount;
});
// Scale the range of the data
x.domain(d3.extent(data, function(d) { return d.Year}));
y.domain([0, d3.max(data, function(d) { return d.Amount; })]);
// Add the valueline path.
svg.append("path")
.data([data])
.attr("class", "line")
.attr("d", valueline);
// Add the X Axis
svg.append("g")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x));
// text label for the x axis
svg.append("text")
.attr("transform",
"translate(" + (width/2) + " ," +
(height + margin.top) + ")")
.style("text-anchor", "middle")
.text("Year");
// Add the Y Axis
svg.append("g")
.call(d3.axisLeft(y));
// text label for the y axis
svg.append("text")
.attr("transform", "rotate(-90)")
.attr("y", 0 - margin.left)
.attr("x",0 - (height / 2))
.attr("dy", "1em")
.style("text-anchor", "middle")
.text("Amount");
});
</script>
</body>
And here is my csv file:
Year,Amount
1998,103323
1999,57914.9
2003,297.969
2004,921253.8
2007,169869.2
2008,44685.5
2010,86084.5
Thanks,
You should use scaleTime for x axis, not scaleLinear:
var x = d3.scaleTime().range([0, width]);
You also should process your dataset this way:
var parseTime = d3.timeParse("%Y");
data.forEach(function(d) {
d.Year = parseTime(d.Year);
d.Amount = +d.Amount;
});
Check working example in the hidden snippet below:
var dataAsCsv = `Year,Amount
1998,103323
1999,57914.9
2003,297.969
2004,921253.8
2007,169869.2
2008,44685.5
2010,86084.5`;
// set the dimensions and margins of the graph
var margin = {top: 50, right: 50, bottom: 100, left: 80},
width = 960 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
// set the ranges
var x = d3.scaleTime().range([0, width]);
var y = d3.scaleLinear().range([height, 0]);
// define the line
var valueline = d3.line()
.x(function(d) { return x(d.Year); })
.y(function(d) { return y(d.Amount); });
// append the svg obgect to the body of the page
// appends a 'group' element to 'svg'
// moves the 'group' element to the top left margin
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 + ")");
var data = d3.csvParse(dataAsCsv);
var parseTime = d3.timeParse("%Y");
// format the data
data.forEach(function(d) {
d.Year = parseTime(d.Year);
d.Amount = +d.Amount;
});
// Scale the range of the data
x.domain(d3.extent(data, function(d) { return d.Year}));
y.domain([0, d3.max(data, function(d) { return d.Amount; })]);
// Add the valueline path.
svg.append("path")
.data([data])
.attr("class", "line")
.attr("d", valueline);
// Add the X Axis
svg.append("g")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x));
// text label for the x axis
svg.append("text")
.attr("transform",
"translate(" + (width/2) + " ," +
(height + margin.top) + ")")
.style("text-anchor", "middle")
.text("Year");
// Add the Y Axis
svg.append("g")
.call(d3.axisLeft(y));
// text label for the y axis
svg.append("text")
.attr("transform", "rotate(-90)")
.attr("y", 0 - margin.left)
.attr("x",0 - (height / 2))
.attr("dy", "1em")
.style("text-anchor", "middle")
.text("Amount");
.line {
fill: none;
stroke: steelblue;
stroke-width: 2px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.13.0/d3.js"></script>

d3 version 4 path line smooth transition with Mike Bostock's example

My first time to post question here. I am converting my version 3 of d3 path line transition code to version 4, and I am having a hard time.
First of all, I saw Mike's example (posted about two days agao) of smooth line transition with non-time x axis for version 4, so I did the similar thing to his example of version 3 with time x axis. The path line moves smoothly, but the x axis doesn't. Also, for my work, I cannot trigger the transition from where he did in this example, so I cannot use the variable "this" in the tick function. Here is the code:
<!DOCTYPE html>
<head>
<meta charset="utf-8">
<script src="//d3js.org/d3.v4.min.js"></script>
<style>
.line {
fill: none;
stroke: #000;
stroke-width: 1.5px;
}
</style>
</head>
<body>
<svg width="960" height="500"></svg>
<script>
(function() {
var n = 243,
duration = 750,
now = new Date(Date.now() - duration),
count = 0,
data = d3.range(n).map(function() { return 0; });
random = d3.randomNormal(0, .2),
data = d3.range(n).map(random);
var margin = {top: 6, right: 0, bottom: 20, left: 40},
width = 960 - margin.right,
height = 120 - margin.top - margin.bottom;
var x = d3.scaleTime()
.domain([now - (n - 2) * duration, now - duration])
.range([0, width]);
var y = d3.scaleLinear()
.range([height, 0]);
var line = d3.line()
.x(function(d, i) { return x(now - (n - 1 - i) * duration); })
.y(function(d, i) { return y(d); });
var svg = d3.select("body").append("p").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.style("margin-left", -margin.left + "px")
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
svg.append("defs").append("clipPath")
.attr("id", "clip")
.append("rect")
.attr("width", width)
.attr("height", height);
var axis = svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(x.axis = d3.axisBottom().scale(x));
var timeline = svg.append("g")
.attr("clip-path", "url(#clip)")
.append("path")
.datum(data)
.attr("class", "line")
.transition()
.duration(500)
.ease(d3.easeLinear)
.on("start", tick);
var transition = d3.select({}).transition()
.duration(750)
.ease(d3.easeLinear);
function tick() {
data.push(random());
now = new Date();
x.domain([now - (n - 2) * duration, now - duration]);
y.domain([0, d3.max(data)]);
// redraw the line
svg.select(".line")
.attr("d", line)
.attr("transform", null);
// slide the x-axis left
axis.call(x.axis);
// slide the line left
d3.active(this)
.attr("transform", "translate(" + x(now - (n - 1) * duration) + ")")
.transition().on("start", tick);
// pop the old data point off the front
data.shift();
}
})()
</script>
</body>
at the tick function, there is a "this", from debugging, I found out it's a path, so I tried to replace it with d3.active(d3.selectAll("path")), or d3.active(d3.selectAll(".line")), neither works. I also tried to assign a variable timeline to the path, so that I tried d3.active(timeline). It doesn't work either.
I am at my wits' end on this issue. I posted on d3 google group, nobody answered. I hope somebody here can give me some suggestions.
Thanks
Diana
The transition to v4 is indeed not easy. Had the same issue as you. Try the following code:
<!DOCTYPE html>
<head>
<meta charset="utf-8">
<script src="//d3js.org/d3.v4.min.js"></script>
<style>
.line {
fill: none;
stroke: #000;
stroke-width: 1.5px;
}
</style>
</head>
<body>
<svg width="960" height="500"></svg>
<script>
(function() {
var n = 243,
duration = 750,
now = new Date(Date.now() - duration),
count = 0,
data = d3.range(n).map(function() {
return 0;
});
random = d3.randomNormal(0, .2),
data = d3.range(n).map(random);
var margin = {top: 6, right: 0, bottom: 20, left: 40},
width = 960 - margin.right,
height = 120 - margin.top - margin.bottom;
var x = d3.scaleTime()
.domain([now - (n - 2) * duration, now - duration])
.range([0, width]);
var y = d3.scaleLinear()
.range([height, 0]);
var line = d3.line()
.x(function(d, i) {
return x(now - (n - 1 - i) * duration);
})
.y(function(d, i) {
return y(d);
});
var svg = d3.select("body").append("p").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.style("margin-left", -margin.left + "px")
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
svg.append("defs").append("clipPath")
.attr("id", "clip")
.append("rect")
.attr("width", width)
.attr("height", height);
var axis = svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(x.axis = d3.axisBottom().scale(x));
var timeline = svg.append("g")
.attr("clip-path", "url(#clip)")
.append("path")
.datum(data)
.attr("class", "line")
.transition()
.duration(500)
.ease(d3.easeLinear);
var transition = d3.select({}).transition()
.duration(750)
.ease(d3.easeLinear);
(function tick() {
transition = transition.each(function() {
data.push(random());
now = new Date();
x.domain([now - (n - 2) * duration, now - duration]);
y.domain([0, d3.max(data)]);
// redraw the line
svg.select(".line")
.attr("d", line)
.attr("transform", null);
// slide the x-axis left
axis.call(d3.axisBottom(x));
// slide the line left
//d3.active(this).attr("transform", "translate(" + x(now - (n - 1) * duration) + ")");
// pop the old data point off the front
data.shift();
}).transition().on("start", tick);
})();
})()
</script>
</body>
The trick is to chain transitions and using transition().on rather than transition().each. To update the axis you need to call the d3.axisBottom(x) in the same way that you instantiate the axis.

normal bars positioning on d3.js bar chart

I try to make a bar chart on the basis of 2D data array (I din`t want to use 2D array initially, so there is a function "mergingAr", which merges them) using d3.js. Here is the code:
.bar {
fill: steelblue;
}
.bar:hover {
fill: brown;
}
var arr1 = [399200,100000, 352108, 600150, 39000, 17005, 4278];
var arr2 = [839, 149, 146, 200, 200, 121, 63];
function mergingAr (array1, array2)
{
var i, out = [];//literal new array
for(i=0;i<array1.length;i++)
{
out.push([array1[i],array2[i]]);
}
return out;
}
var data = mergingAr(arr1, arr2);
margin = {top: 20, right: 20, bottom: 30, left: 40},
width = 960 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
var x = d3.scale.linear()
.domain([0, d3.max(data, function(d) {
return d[0]; })])
.range([0, width]);
var y = d3.scale.linear()
.domain([0, d3.max(data, function(d) { return d[1]; })])
.range([height, 0]);
var xAxis = d3.svg.axis()
.scale(x)
.orient("bottom");
var yAxis = d3.svg.axis()
.scale(y)
.orient("left");
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 + ")");
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
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")
svg.selectAll(".bar")
.data(data)
.enter().append("rect")
.attr("class", "bar")
.attr("x", function(d) { return x(d[0]); })
//.attr("width", x.rangeBand())
.attr("width", width/a1.length)
.attr("y", function(d) { return y(d[1]); })
.attr("height", function(d) { return height - y(d[1]); });
Te problem is - the bars cover each other, there are no distance between them, even if I used rangeRoundBands.
There are 2 issues in your code.
The first one is that the data array is not sorted. In order to sort it you can do:
out = out.sort(function(a,b) { return d3.ascending(a[0],b[0]) })
before returning out in your mergeAt function. Sorting the array makes sure that you process bars in the right order.
The second issue is that your intervals are not equal. To remediate to this, I made the width of a block equal to the distance to the next one (but you might want to do something different):
.attr("width", function(d,i){
if(i!=(data.length-1)) {
return x(data[i+1][0])-x(data[i][0])
} else {
return 10; // the last block is of width 10. a cleaner way is to add a
// marker at the end of the array to know where to finish
// the axis
}
})
JsFiddle: http://jsfiddle.net/chrisJamesC/6WJPA/
Edit
In order to have the same interval between each bar and the same width, you have to change the scale to an ordinal one:
var x = d3.scale.ordinal()
.rangeRoundBands([0, width], .1)
.domain(data.map(function(d){return d[0]}))
Then, you need to change the way you compute the width to:
.attr("width", x.rangeBand())
JsFiddle: http://jsfiddle.net/chrisJamesC/6WJPA/2/

Resources