D3.js interpolateCubehelix() Function

Last Updated : 24 Jul, 2020

The d3.interpolateCubehelix() function in D3.js is used to return the cubehelix color space interpolator function. It takes two colors as a parameter.

Syntax:

d3.interpolateCubehelix(a, b);

d3.interpolateCubehelix.gamma(k)(a, b);

Parameters: It takes two parameters.

a: It is the name of the color of datatype string.
b: It is also the name of the color of type string.

Returns: It returns the interpolator function.

Below given are a few examples of the above function.

Example 1:

<!DOCTYPE html> 
<html lang="en"> 
<head> 
  <meta charset="UTF-8"> 
  <meta name="viewport" 
        content="width=device-width,  
                 initial-scale=1.0"> 
  <title>Document</title> 
</head> 
<style> 
</style> 
<body> 
  <!--fetching from CDN of D3.js -->
  <script type = "text/javascript" 
          src = "https://d3js.org/d3.v4.min.js"> 
  </script> 
  <script> 
    // Printing the return type of the function 
    console.log( 
"function type is: ", typeof(d3.interpolateCubehelix("blue", "white"))) 
    // Using function d3.interpolateCubehelix() 
    console.log( 
"A RGB string: ", d3.interpolateCubehelix("blue", "white")(0.5)) 
    //using gamma 
    console.log( 
"A RGB string", d3.interpolateCubehelix.gamma(2)("blue", "white")(0.2)) 
  </script> 
</body> 
</html> 

Output:

Example 2:

<!DOCTYPE html> 
<html lang="en"> 
<head> 
  <meta charset="UTF-8"> 
  <meta name="viewport" 
        content="width=device-width,  
                 initial-scale=1.0"> 
  <title>Document</title> 
</head> 
<style> 
  .box1, .box2{ 
    display: flex; 
    margin-bottom: 40px; 
    color: white; 
    border: 2px solid black; 
    width: fit-content; 
    height: 150px; 
  } 
</style> 
<body> 
  D3.interpolateCubehelix() 
  <div> 
    <div class="box1"> 
d3.interpolateCubehelix.gamma(10)("green", "white")(0.5) 
    </div> 
    <div class="box2"> 
d3.interpolateCubehelix("green", "white")(0.5) 
    </div> 
  </div> 
  <!--fetching from CDN of D3.js -->
  <script type = "text/javascript" 
          src = "https://d3js.org/d3.v4.min.js"> 
  </script> 
  <script> 
    let box1=document.querySelector(".box1"); 
    let box2=document.querySelector(".box2"); 
    // Please note the effect of gamma 
    let color= 
d3.interpolateCubehelix.gamma(10)("green", "white")(0.5); 
    let color2= 
d3.interpolateCubehelix("green", "white")(0.5);  
    // Changing css of the div with class-name box1 
    box1.style.backgroundColor=color; 
    // Changing css of the div with class-name box2 
    box2.style.backgroundColor=color2; 
  </script> 
</body> 
</html> 