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Programmatic Pan+Zoom
license: gpl-3.0
redirect: https://observablehq.com/@d3/programmatic-zoom

After panning or zooming with the mouse, click the "Reset" button in the top-right corner to transition back to the default viewport. This example demonstrates setting the domain of scales attached to a zoom behavior programmatically. After the domains are set, you must rebind them to the behavior.

See also a simpler version without transitions and a version with buttons that zoom around the center.

<!DOCTYPE html>
<meta charset="utf-8">
<title>Zoom + Pan</title>
<style>
body {
position: relative;
width: 960px;
}
svg {
font: 10px sans-serif;
shape-rendering: crispEdges;
}
rect {
fill: #ddd;
}
.axis path,
.axis line {
fill: none;
stroke: #fff;
}
button {
position: absolute;
right: 30px;
top: 30px;
}
</style>
<button>Reset</button>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>
var 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([-width / 2, width / 2])
.range([0, width]);
var y = d3.scale.linear()
.domain([-height / 2, height / 2])
.range([height, 0]);
var xAxis = d3.svg.axis()
.scale(x)
.orient("bottom")
.tickSize(-height);
var yAxis = d3.svg.axis()
.scale(y)
.orient("left")
.ticks(5)
.tickSize(-width);
var zoom = d3.behavior.zoom()
.x(x)
.y(y)
.scaleExtent([1, 10])
.on("zoom", zoomed);
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 + ")")
.call(zoom);
svg.append("rect")
.attr("width", width)
.attr("height", height);
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
svg.append("g")
.attr("class", "y axis")
.call(yAxis);
d3.select("button").on("click", reset);
function zoomed() {
svg.select(".x.axis").call(xAxis);
svg.select(".y.axis").call(yAxis);
}
function reset() {
d3.transition().duration(750).tween("zoom", function() {
var ix = d3.interpolate(x.domain(), [-width / 2, width / 2]),
iy = d3.interpolate(y.domain(), [-height / 2, height / 2]);
return function(t) {
zoom.x(x.domain(ix(t))).y(y.domain(iy(t)));
zoomed();
};
});
}
</script>
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