CMSISDSP
Version 1.5.2
CMSIS DSP Software Library

Functions  
void  arm_std_f32 (float32_t *pSrc, uint32_t blockSize, float32_t *pResult) 
Standard deviation of the elements of a floatingpoint vector. More...  
void  arm_std_q15 (q15_t *pSrc, uint32_t blockSize, q15_t *pResult) 
Standard deviation of the elements of a Q15 vector. More...  
void  arm_std_q31 (q31_t *pSrc, uint32_t blockSize, q31_t *pResult) 
Standard deviation of the elements of a Q31 vector. More...  
Calculates the standard deviation of the elements in the input vector. The underlying algorithm is used:
Result = sqrt((sumOfSquares  sum^{2} / blockSize) / (blockSize  1))
where, sumOfSquares = pSrc[0] * pSrc[0] + pSrc[1] * pSrc[1] + ... + pSrc[blockSize1] * pSrc[blockSize1]
sum = pSrc[0] + pSrc[1] + pSrc[2] + ... + pSrc[blockSize1]
There are separate functions for floating point, Q31, and Q15 data types.
[in]  *pSrc  points to the input vector 
[in]  blockSize  length of the input vector 
[out]  *pResult  standard deviation value returned here 
References arm_sqrt_f32(), blockSize, mean, and var.
Referenced by main().
[in]  *pSrc  points to the input vector 
[in]  blockSize  length of the input vector 
[out]  *pResult  standard deviation value returned here 
Scaling and Overflow Behavior:
References __SIMD32, __SMLALD(), arm_sqrt_q15(), and blockSize.
[in]  *pSrc  points to the input vector 
[in]  blockSize  length of the input vector 
[out]  *pResult  standard deviation value returned here 
Scaling and Overflow Behavior:
References arm_sqrt_q31(), and blockSize.