JavaScript Math method: atan2()
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The atan2() method (of the Math object)
returns the (principal) arctangent of a real number.
It
has the following syntax with the following parameters:
Math.atan2(y,x)
|
Parameter
|
Required / Optional
|
Description
|
|
y
|
Required
|
y-coordinate
|
|
x
|
Required
|
x-coordinate
|
Note: many computer
languages have an atan2 function, but the ordering of the parameters is not the
same across all languages
EXAMPLE:
HTML USED IN THIS EXAMPLE:
<!DOCTYPE html>
<html> <!-- Copyright (c) Nematrian Limited 2018 -->
<head>
<style>
table,th,tr,td {border: 1px solid black; border-collapse: collapse;}
</style>
</head>
<body>
<table>
<tr>
<th>Example</th>
<th>Resulting value of <code>x</code></th>
</tr>
<tr>
<td><code id="Example"></code></td>
<td><code id="Result"></code></td>
</tr>
</table>
<script>
var b = -0.2;
var b2 = 0.3;
document.getElementById("Example").innerHTML =
'var x = Math.atan2(' + b + ', ' + b2 + ')';
document.getElementById("Result").innerHTML = Math.atan2(b,b2);
</script>
</body>
</html>
|
FUNCTION THAT MAY ASSIST IN TESTING WHETHER FEATURE IS SUPPORTED:
function isSupportedJavaScriptMethodMathAtan2() {
return !!Math.atan2(12.5, 0.5);
} |
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