Skip to content
Related Articles

Related Articles

Improve Article

D3.js zoom.scaleTo() Function

  • Last Updated : 31 Aug, 2020
Geek Week

The zoom.scaleTo() function in D3.js is used to scale the current zoon transform of the selected elements to k.

Syntax:

zoom.scaleTo(selection, k[, p])

Parameters: This function accept two parameter as mentioned above and described below

  • selection: This parameter can be selection or transition.
  • k: This parameter is a scale factor, specified either as numbers or as functions

Return Value: This function returns the zoom behavior.

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



Example 1:

HTML




<!DOCTYPE html> 
<html
<head
    <meta charset="utf-8">
      
    <script src="https://d3js.org/d3.v4.min.js"
    </script>
      
    <style>
        circle {
          opacity: 0.7;
        }
        g.zoom-controls {
            cursor: pointer;
            pointer-events: all;
        }
        g.zoom-controls rect {
            fill: white;
            stroke: #596877;
            stroke-width: 1;
        }
        g.zoom-controls line {
            stroke: #596877;
            stroke-width: 2;
        }
    </style>
     
</head
    
<body
    <center>
        <h1 style="color: green;"
            Geeksforgeeks 
        </h1
      
        <h3>D3.js | zoom.scaleTo() Function</h3>
          
        <svg>
          <g class="zoom-controls" transform="translate(10, 10)">
            <g id="zoom-in" transform="translate(0, 0)">
              <rect width="30" height="30"></rect>
              <line x1="5" y1="15" x2="25" y2="15"></line>
              <line x1="15" y1="5" x2="15" y2="25"></line>
            </g>
            <g id="zoom-out" transform="translate(30, 0)">
              <rect width="30" height="30"></rect>
              <line x1="5" y1="15" x2="25" y2="15"></line>
            </g>
          </g>
        </svg>
          
        <script>
            var radius = 10;
            var svg = d3.select('svg');  
            var dimension = document.body.getBoundingClientRect();
              
            var data = d3.range(0, 25).map(function() {
                return {
                x: getRandom(radius, dimension.width - radius),
                y: getRandom(radius, dimension.height - radius)
              }
            });
              
            var zoom = d3.zoom()
                .on('zoom', function() {
                canvas.attr('transform', d3.event.transform);
              })
              
            var canvas = svg
                .attr('width', dimension.width)
              .attr('height', dimension.height)
              .call(zoom)
              .insert('g', ':first-child');
            canvas.selectAll('circle')
              .data(data)
              .enter()
              .append('circle')
              .attr('r', radius)
              .attr('cx', function(d) {
                return d.x;
              }).attr('cy', function(d) {
                return d.y;
              }).style('fill', function() {
                return d3.schemeCategory10[getRandom(0, 9)]
              });
              
            d3.select('#zoom-in').on('click', function() {
              // Smooth zooming
                zoom.scaleTo(svg.transition().duration(750), 1.3);
            });
              
            d3.select('#zoom-out').on('click', function() {
              // Ordinal zooming
              zoom.scaleTo(svg, 1 / 1.3);
            });
              
              
            function getRandom(min, max) {
              min = Math.ceil(min);
              max = Math.floor(max);
              return Math.floor(Math.random() 
                     * (max - min + 1)) + min;
            }
        </script
    </center>
</body
  
</html

Output:

Example 2:

HTML




<!DOCTYPE html> 
<html
<head
    <meta charset="utf-8">
      
    <script src="https://d3js.org/d3.v5.js">
    </script>
      
</head
    
<body
    <center>
        <h1 style="color: green;"
            Geeksforgeeks 
        </h1
      
        <h3>D3.js | zoom.scaleTo() Function</h3>
          
        <svg height="100px" width="100px"></svg>
          
        <script>
        const zoom_action = () => g.attr("transform", d3.event.transform)
  
        // Create the zoom handler
        const zoom = d3
                .zoom()
                .on("zoom", zoom_action)
          
        // Get SVG element and apply zoom behaviour
        var svg = d3
          .select("svg")
          .call(zoom)
          
        // Create Group that will be zoomed
        var g = svg.append("g")
          
        // Create circle
        g.append("circle")
          .attr("cx",0)
          .attr("cy",0)
          .attr("r", 5)
          .style("fill","green")
          
        // Use of zoom.scaleTo Function
        zoom.scaleTo(svg, 5)
        zoom.translateBy(svg, 50, 50) 
  
        </script
    </center>
</body
  
</html

Output:

Hey geek! The constant emerging technologies in the world of web development always keeps the excitement for this subject through the roof. But before you tackle the big projects, we suggest you start by learning the basics. Kickstart your web development journey by learning JS concepts with our JavaScript Course. Now at it’s lowest price ever!




My Personal Notes arrow_drop_up
Recommended Articles
Page :