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CMSIS DSP library

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Mean
Functions

Mean
[Statistics Functions]

Calculates the mean of the input vector. More...

Functions

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

Detailed 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 ( float32_t *  pSrc,
uint32_t  blockSize,
float32_t *  pResult 
)

Mean value of a floating-point vector.

Parameters:
[in]*pSrcpoints to the input vector
[in]blockSizelength of the input vector
[out]*pResultmean value returned here
Returns:
none.

Definition at line 75 of file arm_mean_f32.c.

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

Mean value of a Q15 vector.

Parameters:
[in]*pSrcpoints to the input vector
[in]blockSizelength of the input vector
[out]*pResultmean 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 saturated and truncated to yield a result of 1.15 format.

Definition at line 72 of file arm_mean_q15.c.

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

Mean value of a Q31 vector.

Parameters:
[in]*pSrcpoints to the input vector
[in]blockSizelength of the input vector
[out]*pResultmean 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.

Definition at line 72 of file arm_mean_q31.c.

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

Mean value of a Q7 vector.

Parameters:
[in]*pSrcpoints to the input vector
[in]blockSizelength of the input vector
[out]*pResultmean 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.

Definition at line 72 of file arm_mean_q7.c.

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