ArcTan2

Functions
arm_status	arm_atan2_f16 (float16_t y, float16_t x, float16_t *result)
	Arc Tangent of y/x using sign of y and x to get right quadrant.
arm_status	arm_atan2_f32 (float32_t y, float32_t x, float32_t *result)
	Arc Tangent of y/x using sign of y and x to get right quadrant.
arm_status	arm_atan2_q15 (q15_t y, q15_t x, q15_t *result)
	Arc Tangent of y/x using sign of y and x to get right quadrant.
arm_status	arm_atan2_q31 (q31_t y, q31_t x, q31_t *result)
	Arc Tangent of y/x using sign of y and x to get right quadrant.

Description

Computing Arc tangent only using the ratio y/x is not enough to determine the angle since there is an indeterminacy. Opposite quadrants are giving the same ratio.

ArcTan2 is not using y/x to compute the angle but y and x and use the sign of y and x to determine the quadrant.

Function Documentation

arm_atan2_f16()

arm_status arm_atan2_f16	(	float16_t	y,
		float16_t	x,
		float16_t *	result
	)

Arc Tangent of y/x using sign of y and x to get right quadrant.

Arc tangent in radian of y/x using sign of x and y to determine right quadrant.

Parameters

[in]	y	y coordinate
[in]	x	x coordinate
[out]	result	Result

Returns

error status.

Compute the Arc tangent of y/x:

The sign of y and x are used to determine the right quadrant and compute the right angle. Returned value is between -Pi and Pi.

arm_atan2_f32()

arm_status arm_atan2_f32	(	float32_t	y,
		float32_t	x,
		float32_t *	result
	)

Arc Tangent of y/x using sign of y and x to get right quadrant.

Arc tangent in radian of y/x using sign of x and y to determine right quadrant.

Parameters

[in]	y	y coordinate
[in]	x	x coordinate
[out]	result	Result

Returns

error status.

Compute the Arc tangent of y/x:

The sign of y and x are used to determine the right quadrant and compute the right angle. Returned value is between -Pi and Pi.

arm_atan2_q15()

arm_status arm_atan2_q15	(	q15_t	y,
		q15_t	x,
		q15_t *	result
	)

Arc Tangent of y/x using sign of y and x to get right quadrant.

Arc tangent in radian of y/x using sign of x and y to determine right quadrant.

Parameters

[in]	y	y coordinate
[in]	x	x coordinate
[out]	result	Result in Q2.13

Returns

error status.

Compute the Arc tangent of y/x:

The sign of y and x are used to determine the right quadrant and compute the right angle. Returned value is between -Pi and Pi.

arm_atan2_q31()

arm_status arm_atan2_q31	(	q31_t	y,
		q31_t	x,
		q31_t *	result
	)

Arc Tangent of y/x using sign of y and x to get right quadrant.

Arc tangent in radian of y/x using sign of x and y to determine right quadrant.

Parameters

[in]	y	y coordinate
[in]	x	x coordinate
[out]	result	Result in Q2.29

Returns

error status.

Compute the Arc tangent of y/x:

The sign of y and x are used to determine the right quadrant and compute the right angle. Returned value is between -Pi and Pi.