The d3.scaleThreshold() function in D3.js is used to create and return a new threshold scale that has the specified domain and range. The default value of domain is [0.5] and that of range is [0, 1].
Syntax:
d3.scaleThreshold( domain, range )
Parameters: This function accepts two parameters as given above and described below:
- domain: It defines the minimum and maximum value for the scale. It is an optional parameter. The default value is [0.5].
- range: It accepts a range of discrete values, Every value in domain maps with a value in the range. It is an optional parameter. The default range is [0, 1].
Return Values: This function does not return anything.
Below programs illustrate the d3.scaleThreshold() function in D3.js:
Example 1:
<!DOCTYPE html>
<html>
<head>
<script src="https://d3js.org/d3.v4.min.js">
</script>
</head>
<body>
<h2 style="color: green;">GeekforGeeks</h2>
<p>d3.scaleThreshold() Function </p>
<script>
var threshold = d3.scaleThreshold()
// Setting domain and range for the scale
.domain([10])
.range(["red", "green", "black", "blue"]);
document.write("<h4>" + threshold(9) + "</h4>");
document.write("<h4>" + threshold(10) + "</h4>");
</script>
</body>
</html>
Output:
Example 2:
<!DOCTYPE html>
<html>
<head>
<script src="https://d3js.org/d3.v4.min.js">
</script>
</head>
<body>
<h2 style="color: green;">GeekforGeeks</h2>
<p>d3.scaleThreshold() Function </p>
<script>
var threshold = d3.scaleThreshold()
// Setting domain and range for the scale
.domain([1, 2, 10])
.range([0, 1, 2, 3]);
document.write("<h4>" + threshold(2) + "</h4>");
document.write("<h4>" + threshold(10) + "</h4>");
</script>
</body>
</html>
Output:
