Library for adding snapping to a d3 brush.
<!DOCTYPE html>
<script src="https://cdn.jsdelivr.net/npm/d3@7"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/d3-brush-tooltip@1.0.1"></script>
<script src="https://cdn.jsdelivr.net/npm/humanize-duration@3.32.1"></script>
<script src="https://cdn.jsdelivr.net/npm/d3-brush-snapping@1.0.0"></script>
<link rel="stylesheet" href="css/style.css">
<html>
<body>
<h2>Linear Chart with Snapping</h2>
<div id="chart-div">
</div>
<script>
{
// create chart
let width = 600;
let height = 400;
const margin = { top: 10, right: 30, bottom: 30, left: 40 };
width = width - margin.left - margin.right,
height = height - margin.top - margin.bottom;
// append the svg object to the body of the page
var svg = d3.select("#chart-div")
.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 + ")");
const maxX = 1000;
// add x axis
const x = d3.scaleLinear()
.domain([0, maxX])
.range([0, width]);
svg.append("g")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x));
// generate random data
const data = [];
for (let i = 0; i < 1000; i++) {
data.push(Math.random() * maxX);
}
// create bins
const bin = d3.bin()
.domain(x.domain())
.thresholds(x.ticks(20));
const bins = bin(data);
// add y axis
const y = d3.scaleLinear()
.domain([0, d3.max(bins, function (d) { return d.length; })])
.range([height, 0]);
svg.append("g")
.call(d3.axisLeft(y));
// append the bar rectangles to the svg element
svg.selectAll("rect")
.data(bins)
.enter()
.append("rect")
.attr("x", 1)
.attr("transform", function (d) { return "translate(" + x(d.x0) + "," + y(d.length) + ")"; })
.attr("width", function (d) { return Math.max(0, x(d.x1) - x(d.x0) - 1); })
.attr("height", function (d) { return height - y(d.length); })
.style("fill", "#69b3a2")
// add a brush container to the chart
const brushContainer = svg.append("g");
// create the brush
const brush = d3.brushX().extent([[0, 0], [width, height]]);
brushContainer.call(brush);
// move brush to the initial position
const initialSelection = [x(100), x(200)];
brushContainer.call(brush.move, initialSelection);
const snappingThreshold = 50;
const minX = 0;
// add linear snapping to brush
window.d3BrushSnapping.addLinearSnappingToBrush(brush, brushContainer, x, snappingThreshold, minX, maxX);
}
</script>
<h2>Date Range Chart with Snapping</h2>
<div id="time-chart-div">
</div>
<script>
{
// create chart
let width = 600;
let height = 400;
const margin = { top: 10, right: 30, bottom: 30, left: 40 };
width = width - margin.left - margin.right,
height = height - margin.top - margin.bottom;
// append the svg object to the body of the page
var svg = d3.select("#time-chart-div")
.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 + ")");
const maxX = 1000;
const startDate = new Date("2000-01-01");
const endDate = new Date("2000-01-02");
const brushStart = new Date("2000-01-01:06:00:00");
const brushEnd = new Date("2000-01-01:09:00:00");
// add x axis
const x = d3.scaleUtc([startDate, endDate], [0, width]);
svg.append("g")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x));
// generate random data
const data = [];
for (let i = 0; i < 1000; i++) {
const hour = Math.round(Math.random() * 24);
data.push(new Date(Date.UTC(2000, 0, 1, hour, 0, 0, 0)));
}
// create bins
const bin = d3.bin()
.domain(x.domain())
.thresholds(x.ticks(20));
const bins = bin(data);
// add y axis
const y = d3.scaleLinear()
.domain([0, d3.max(bins, function (d) { return d.length; })])
.range([height, 0]);
svg.append("g")
.call(d3.axisLeft(y));
// append the bar rectangles to the svg element
svg.selectAll("rect")
.data(bins)
.enter()
.append("rect")
.attr("x", 1)
.attr("transform", function (d) { return "translate(" + x(d.x0) + "," + y(d.length) + ")"; })
.attr("width", function (d) { return Math.max(0, x(d.x1) - x(d.x0) - 1); })
.attr("height", function (d) { return height - y(d.length); })
.style("fill", "#00619E")
// add a brush container to the chart
const brushContainer = svg.append("g");
// create the brush
const brush = d3.brushX().extent([[0, 0], [width, height]]);
brushContainer.call(brush);
// move brush to the initial position
const initialSelection = [x(brushStart), x(brushEnd)];
brushContainer.call(brush.move, initialSelection);
// add time snapping to brush
window.d3BrushSnapping.addTimeSnappingToBrush(brush, brushContainer, {
timeScale: x,
numTicks: 24,
extentStartMs: startDate.getTime(),
extentEndMs: endDate.getTime(),
brushStartMs: brushStart.getTime(),
brushEndMs: brushEnd.getTime(),
width: width,
});
}
</script>
<h2>Date Range Chart with Snapping (Extent that doesn't align with ticks)</h2>
<div id="irregular-time-chart-div">
<div id="tooltip" class="tooltip-default"></div>
</div>
<script>
{
// create chart
let width = 600;
let height = 400;
const margin = { top: 10, right: 30, bottom: 30, left: 40 };
width = width - margin.left - margin.right,
height = height - margin.top - margin.bottom;
// append the svg object to the body of the page
var svg = d3.select("#irregular-time-chart-div")
.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 + ")");
const maxX = 1000;
const startDate = new Date("1999-12-31T23:25:59.992");
const endDate = new Date("2000-01-02");
const brushStart = new Date("2000-01-01T06:00:00");
const brushEnd = new Date("2000-01-01T09:00:00");
// add x axis
const x = d3.scaleUtc()
.domain([startDate, endDate])
.clamp(true)
.rangeRound([0, width]);
svg.append("g")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x));
// generate random data
const data = [];
for (let i = 0; i < 1000; i++) {
const hour = Math.round(Math.random() * 24);
data.push(new Date(Date.UTC(2000, 0, 1, hour, 0, 0, 0)));
}
// create bins
const bin = d3.bin()
.domain(x.domain())
.thresholds(x.ticks(20));
const bins = bin(data);
// add y axis
const y = d3.scaleLinear()
.domain([0, d3.max(bins, function (d) { return d.length; })])
.range([height, 0]);
svg.append("g")
.call(d3.axisLeft(y));
// append the bar rectangles to the svg element
svg.selectAll("rect")
.data(bins)
.enter()
.append("rect")
.attr("x", 1)
.attr("transform", function (d) { return "translate(" + x(d.x0) + "," + y(d.length) + ")"; })
.attr("width", function (d) { return Math.max(0, x(d.x1) - x(d.x0) - 1); })
.attr("height", function (d) { return height - y(d.length); })
.style("fill", "#00619E")
// add a brush container to the chart
const brushContainer = svg.append("g");
// create the brush
const brush = d3.brushX().extent([[0, 0], [width, height]]);
brushContainer.call(brush);
// move brush to the initial position
const initialSelection = [x(brushStart), x(brushEnd)];
brushContainer.call(brush.move, initialSelection);
let previousResult = {
pixels: initialSelection,
values: [brushStart.getTime(), brushEnd.getTime()],
};
// onSelectionChange, track the snapped result
const onSelectionChanged = (event, snappedResult) => {
previousResult.pixels = snappedResult.pixels;
previousResult.values = snappedResult.values;
};
// add time snapping to brush
window.d3BrushSnapping.addTimeSnappingToBrush(brush, brushContainer, {
timeScale: x,
numTicks: 24,
extentStartMs: startDate.getTime(),
extentEndMs: endDate.getTime(),
brushStartMs: brushStart.getTime(),
brushEndMs: brushEnd.getTime(),
width: width,
allowExtentSnapping: true,
}, onSelectionChanged);
const initialText = humanizeDuration(Math.abs(previousResult.values[1] - previousResult.values[0]), { units: ["w", "d", "h", "m", "s", "ms"], round: true });
const tooltipId = "#tooltip";
// add tooltip to the brush to view time duration
window.d3BrushTooltip.addTooltipToBrush(tooltipId, brush, brushContainer, ({ selection }) => {
let humanReadableDuration = null;
if (!selection) {
humanReadableDuration = initialText;
} else if (selection[0] === selection[1]) {
humanReadableDuration = null;
} else if (previousResult != null) {
humanReadableDuration = humanizeDuration(Math.abs(previousResult.values[1] - previousResult.values[0]), { units: ["w", "d", "h", "m", "s", "ms"], round: true });
}
return humanReadableDuration;
}, initialText);
}
</script>
</body>
</html>