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@harish-r
Created November 30, 2018 03:29
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Demo of Zoom and Pan in a Scatterplot using D3
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<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: 20, right: 20, bottom: 30, left: 50 },
width = 960 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
// 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);
svg.append("defs").append("clipPath")
.attr("id", "clip")
.append("rect")
.attr("width", width)
.attr("height", height);
// set the ranges
var x = d3.scaleLinear().range([0, width]);
var y = d3.scaleLinear().range([height, 0]);
// scale the range of the data
x.domain([-50, 50]);
y.domain([-50, 50]);
var xAxis = d3.axisBottom(x);
var yAxis = d3.axisLeft(y);
// add the X Axis
var gX = svg.append("g")
.attr("transform", "translate(" + margin.left + ", " + (margin.top + height) + ")")
.call(xAxis);
// add the Y Axis
var gY = svg.append("g")
.attr("transform", "translate(" + margin.left + ", " + margin.top + ")")
.call(yAxis);
// Zoom functionality
var zoom = d3.zoom()
.scaleExtent([.5, 20])
.extent([[0, 0], [width, height]])
.on("zoom", zoomed);
var event_rect = svg.append("rect")
.attr("width", width)
.attr("height", height)
.style("fill", "none")
.style("pointer-events", "all")
.attr('transform', 'translate(' + margin.left + ',' + margin.top + ')')
.call(zoom);
var points_g = svg.append("g")
.attr('transform', 'translate(' + margin.left + ',' + margin.top + ')')
.attr("clip-path", "url(#clip)");
// .classed("points_g", true);
var getdata = function() {
var dataset = []
for (var i = 0; i < 20; i++) {
var x = d3.randomUniform(-50, 50)();
var y = d3.randomUniform(-50, 50)();
dataset.push({ "x": x, "y": y });
}
return dataset;
}
// Get the data
var data = getdata()
// format the data
data.forEach(function(d) {
d.x = +d.x;
d.y = +d.y;
});
// add the dots
var points = points_g.selectAll("circle")
.data(data)
.enter()
.append("circle")
.attr("r", 5)
.attr("cx", function(d) { return x(d.x); })
.attr("cy", function(d) { return y(d.y); })
.on('click', function(d, i) {
})
.on('mouseover', function(d, i) {
console.log("Mouse over");
});
function zoomed() {
var new_x = d3.event.transform.rescaleX(x);
var new_y = d3.event.transform.rescaleY(y);
// update axes
gX.call(xAxis.scale(new_x));
gY.call(yAxis.scale(new_y));
points.data(data)
.attr('cx', function(d) {return new_x(d.x)})
.attr('cy', function(d) {return new_y(d.y)});
}
</script>
</body>
</html>
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