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@d3noob
Last active October 29, 2022 01:38
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Filtering in d3.js
license: mit

This is a follow on from the simple scatterplot used as an example in the book D3 Tips and Tricks.

It is aimed at demonstrating the use of the .filter statement in d3.js and should be taken in context with the text of the book which can be downloaded for free from Leanpub.

date close
1-May-12 58.13
30-Apr-12 53.98
27-Apr-12 67.00
26-Apr-12 89.70
25-Apr-12 99.00
24-Apr-12 130.28
23-Apr-12 166.70
20-Apr-12 234.98
19-Apr-12 345.44
18-Apr-12 443.34
17-Apr-12 543.70
16-Apr-12 580.13
13-Apr-12 605.23
12-Apr-12 622.77
11-Apr-12 626.20
10-Apr-12 628.44
9-Apr-12 636.23
5-Apr-12 633.68
4-Apr-12 624.31
3-Apr-12 629.32
2-Apr-12 618.63
30-Mar-12 599.55
29-Mar-12 609.86
28-Mar-12 617.62
27-Mar-12 614.48
26-Mar-12 606.98
<!DOCTYPE html>
<meta charset="utf-8">
<style> /* set the CSS */
body { font: 12px Arial;}
path {
stroke: steelblue;
stroke-width: 2;
fill: none;
}
.axis path,
.axis line {
fill: none;
stroke: grey;
stroke-width: 1;
shape-rendering: crispEdges;
}
</style>
<body>
<!-- load the d3.js library -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.min.js"></script>
<script>
// Set the dimensions of the canvas / graph
var margin = {top: 30, right: 20, bottom: 30, left: 50},
width = 600 - margin.left - margin.right,
height = 270 - margin.top - margin.bottom;
// Parse the date / time
var parseDate = d3.time.format("%d-%b-%y").parse;
// Set the ranges
var x = d3.time.scale().range([0, width]);
var y = d3.scale.linear().range([height, 0]);
// Define the axes
var xAxis = d3.svg.axis().scale(x)
.orient("bottom").ticks(5);
var yAxis = d3.svg.axis().scale(y)
.orient("left").ticks(5);
// Define the line
var valueline = d3.svg.line()
.x(function(d) { return x(d.date); })
.y(function(d) { return y(d.close); });
// Adds the svg canvas
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("data.csv", function(error, data) {
data.forEach(function(d) {
d.date = parseDate(d.date);
d.close = +d.close;
});
// Scale the range of the data
x.domain(d3.extent(data, function(d) { return d.date; }));
y.domain([0, d3.max(data, function(d) { return d.close; })]);
// Add the valueline path.
svg.append("path")
.attr("class", "line")
.attr("d", valueline(data));
// Add the scatterplot
svg.selectAll("dot")
.data(data)
.enter().append("circle")
.filter(function(d) { return d.close < 400 })
.style("fill", "red")
.attr("r", 3.5)
.attr("cx", function(d) { return x(d.date); })
.attr("cy", function(d) { return y(d.close); });
// Add the X Axis
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
// Add the Y Axis
svg.append("g")
.attr("class", "y axis")
.call(yAxis);
});
</script>
</body>
@SinonCuriosus
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Is it there a way to select the columns in a dynamic way? Like I was d.Wage_2011 and d.Wage_2022, but I want to select a certain column depending on a user checkbox...Which way would you recommend? By the way, thanks for the way to filter rows.

@d3noob
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d3noob commented Oct 29, 2022

I think that the function you are looking for is the 'brush' function. I haven't used it for any of my examples, so Google will probably need to be youre friend. Good uck.

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