Mean

Functions
void	arm_mean_f32 (const float32_t *pSrc, uint32_t blockSize, float32_t *pResult)
	Mean value of a floating-point vector. More...
void	arm_mean_q15 (const q15_t *pSrc, uint32_t blockSize, q15_t *pResult)
	Mean value of a Q15 vector. More...
void	arm_mean_q31 (const q31_t *pSrc, uint32_t blockSize, q31_t *pResult)
	Mean value of a Q31 vector. More...
void	arm_mean_q7 (const q7_t *pSrc, uint32_t blockSize, q7_t *pResult)
	Mean value of a Q7 vector. More...

Description

Calculates the mean of the input vector. Mean is defined as the average of the elements in the vector. The underlying algorithm is used:

    Result = (pSrc[0] + pSrc[1] + pSrc[2] + ... + pSrc[blockSize-1]) / blockSize;

There are separate functions for floating-point, Q31, Q15, and Q7 data types.

Function Documentation

void arm_mean_f32	(	const float32_t *	pSrc,
		uint32_t	blockSize,
		float32_t *	pResult
	)

Parameters

[in]	pSrc	points to the input vector.
[in]	blockSize	number of samples in input vector.
[out]	pResult	mean value returned here.

Returns

none

void arm_mean_q15	(	const q15_t *	pSrc,
		uint32_t	blockSize,
		q15_t *	pResult
	)

Parameters

[in]	pSrc	points to the input vector
[in]	blockSize	number of samples in input vector
[out]	pResult	mean value returned here

Returns

none

Scaling and Overflow Behavior

The function is implemented using a 32-bit internal accumulator. The input is represented in 1.15 format and is accumulated in a 32-bit accumulator in 17.15 format. There is no risk of internal overflow with this approach, and the full precision of intermediate result is preserved. Finally, the accumulator is truncated to yield a result of 1.15 format.

void arm_mean_q31	(	const q31_t *	pSrc,
		uint32_t	blockSize,
		q31_t *	pResult
	)

Parameters

[in]	pSrc	points to the input vector
[in]	blockSize	number of samples in input vector
[out]	pResult	mean value returned here

Returns

none

Scaling and Overflow Behavior

The function is implemented using a 64-bit internal accumulator. The input is represented in 1.31 format and is accumulated in a 64-bit accumulator in 33.31 format. There is no risk of internal overflow with this approach, and the full precision of intermediate result is preserved. Finally, the accumulator is truncated to yield a result of 1.31 format.

void arm_mean_q7	(	const q7_t *	pSrc,
		uint32_t	blockSize,
		q7_t *	pResult
	)

Parameters

[in]	pSrc	points to the input vector
[in]	blockSize	number of samples in input vector
[out]	pResult	mean value returned here

Returns

none

Scaling and Overflow Behavior

The function is implemented using a 32-bit internal accumulator. The input is represented in 1.7 format and is accumulated in a 32-bit accumulator in 25.7 format. There is no risk of internal overflow with this approach, and the full precision of intermediate result is preserved. Finally, the accumulator is truncated to yield a result of 1.7 format.