**ATan2()**

**Syntax**

Result.f(.d) =ATan2(x.f(.d), y.f(.d))

Calculates the angle in radian between the x axis and a line drawn in the direction specified by 'x' and 'y'. It can be used to calculate angles between lines in 2D or to transform rectangular coordinates into polar coordinates.

**Parameters**

x.f, y.f or x.d, y.dThe direction of the line to calculate the angle from. Zero values are allowed.

**Return value**

Returns the resulting angle in radian. The result can be transformed into degrees using the Degree() function.

**Remarks**

This function calculates the value ATan(y/x) and examines the sign of x and y to place the angle in the correct quadrant. It also handles the cases where y is zero to avoid division by zero errors.

The result is always between -#PI and +#PI. Negative angles indicate that the line is below the x axis, positive values indicate that line is above the x axis. If 'x' and 'y' are zero then the function returns 0.0.

This function handles and returns float or double values.

**Example**

DebugATan2(10, 10) ; will display #PI/4 (45 degrees in radian)

**See Also**

ATan(), Degree()

**Supported OS **

All