How to re-scale d3.js map after zooming?

by giovanny.lueilwitz , in category: Javascript , a month ago

How to re-scale d3.js map after zooming?

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1 answer

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by domenico , a month ago

@giovanny.lueilwitz 

To re-scale a d3.js map after zooming, you can use the following steps:

  1. Add a zoom event listener to your map element:
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var zoom = d3.zoom()
    .on("zoom", zoomed);

svg.call(zoom);


  1. Define the zoomed function to handle the zoom event and re-scale the map:
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function zoomed() {
  g.attr("transform", d3.event.transform);
}


  1. Update the projection scale and translate based on the zoom scale and transform:
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projection
    .scale(d3.event.transform.k * initialScale)
    .translate([d3.event.transform.x, d3.event.transform.y]);


  1. Update the paths of the map features based on the new projection:
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svg.selectAll("path")
    .attr("d", path);


By following these steps, you can re-scale the d3.js map after zooming and ensure that the map features are correctly updated and displayed at the new scale.