D3.js zoom() Function

Last Updated : 09 Sep, 2020

The d3.zoom() Function in D3.js is used to create a new zoom behaviour. It is used to apply the zoom transformation on a selected element.

Syntax:

d3.zoom();

Parameters: This function does not accept any parameter.

Return Value: This function returns the zoom behaviour.

Below programs illustrate the d3.zoom() function in D3.js

Example 1: This example, Zooming and panning is done. Double click to zoom, the circle gets bigger.

<!DOCTYPE html>  
<html>  
<head>  
    <meta charset="utf-8"> 
    <script src="https://d3js.org/d3.v4.min.js">  
   </script>    
</head>   
<body>  
    <center> 
        <h1 style="color: green;">  
            Geeksforgeeks  
        </h1>  
      
        <h3>D3.js | d3.zoom() Function</h3> 
          
        <div id="GFG"></div> 
          
        <script> 
            var svg = d3.select("#GFG") 
              .append("svg") 
                .attr("width", 300) 
                .attr("height", 300) 
                .call(d3.zoom().on("zoom", function () { 
                   svg.attr("transform", d3.event.transform) 
                })) 
              .append("g") 
              
            svg 
              .append("circle") 
                .attr("cx", 150) 
                .attr("cy", 150) 
                .attr("r", 40) 
                .style("fill", "green") 
              
        </script>  
    </center> 
</body>  
</html>  

Output:

Example 2:

<!DOCTYPE html>  
<html>  
<head>  
    <meta charset="utf-8"> 
    <script src="https://d3js.org/d3.v4.min.js">  
    </script> 
    <style> 
        svg text {   
            fill: green;   
            font: 20px sans-serif;   
            text-anchor: center;   
        }   
          
        rect { 
          pointer-events: all; 
        } 
    </style> 
</head>  
<body>  
    <center> 
        <h1 style="color: green;">  
            Geeksforgeeks  
        </h1>  
      
        <h3>D3.js | d3.zoom() Function </h3> 
          
        <svg></svg> 
          
        <script> 
            var width = 400; 
            var height = 200; 
              
            var svg = d3.select("svg") 
              .attr("width", width) 
              .attr("height", height); 
                
            // The scale used to display the axis. 
            var scale = d3.scaleLinear() 
              .range([10, width-20]) 
              .domain([0, 100]); 
               
            var shadowScale = scale.copy(); 
              
            var axis = d3.axisBottom() 
              .scale(scale); 
                
            var g = svg.append("g") 
              .attr("transform", "translate(0, 50)") 
              .call(axis); 
                
            // Standard zoom behavior: 
            var zoom = d3.zoom() 
              .scaleExtent([1, 10]) 
              .translateExtent([[0, 0], [width, height]]) 
              .on("zoom", zoomed); 
               
            // Call the Zoom. 
            svg.call(zoom); 
        </script>  
    </center> 
</body>  
</html>