Core Function ATan

ATan( <expression>, <expression2> )

Description

Calculates the arctangent of a number.

Parameters

expression

Any valid numeric expression.

expression2

Optional; Any valid numeric expression.

If this param is used this ATan will become ATan2

Return Value

WITH ONE PARAM : Returns the trigonometric arctangent of expression.

WITH TWO PARAMS : Returns the angle whose tangent is the quotient of two specified numbers.

Remarks

The result of 4 * ATan(1) is PI.

Example

// Atan with 1 param
$x = ATan(0.5);
$pi = 4 * ATan(1);
$radToDeg = 180 / @PI;
$y = ATan(1) * $radToDeg;
println( "Value is: $y " ); //arctangent of 1 returns 45°
 
// Atan2 (2 params)
$x = -10.0;
$y = 10.0;
$result = 0;
$result = Atan($y, $x) * 180 / @PI;
printf("The arc tangent for (x=$x, y=$y) is $result degrees.\n");
// Prints The arc tangent for (x=-10.000000, y=10.000000) is 135.000000 degrees.