# FX_Atan2Idx

## Syntax

      #include <nitro/fx/fx_trig.h>

      u16 FX_Atan2Idx( fx32 y, fx32 x );

## Arguments

y | `fx32`-format fixed-point decimal.
x | `fx32`-format fixed-point decimal.

## Return Values

Arctangent of y/x

## Description

This finds the arctangent of `y`/`x`. The results are returned in a `u16` format. The units of the result are equal to 1/65536 of a circle (2 π radians). (Example: A right angle would be 16384.) Internally, a table is referenced.

The divider is used internally. Refer to Divider Usage Notes when using this function inside an interrupt.

## See Also

`FX_Atan, FX_Atan2, FX_AtanIdx, FX_AsinIdx, FX_AcosIdx`

## Revision History

2004/06/16 Initial version.

CONFIDENTIAL