Mean

Computes the mean value of a vector.

Syntax

IppStatus ippsMean_32f(const Ipp32f* pSrc, int len, Ipp32f* pMean, IppHintAlgorithm hint);

IppStatus ippsMean_32fc(const Ipp32fc* pSrc, int len, Ipp32fc* pMean, IppHintAlgorithm hint);

IppStatus ippsMean_64f(const Ipp64f* pSrc, int len, Ipp64f* pMean);

IppStatus ippsMean_64fc(const Ipp64fc* pSrc, int len, Ipp64fc* pMean);

IppStatus ippsMean_16s_Sfs(const Ipp16s* pSrc, int len, Ipp16s* pMean, int scaleFactor);

IppStatus ippsMean_32s_Sfs(const Ipp32s* pSrc,int len,Ipp32s* pMean,int scaleFactor);

IppStatus ippsMean_16sc_Sfs(const Ipp16sc* pSrc, int len, Ipp16sc* pMean, int scaleFactor);

Parameters

pSrc	Pointer to the source vector.
pMean	Pointer to the output result.
len	Number of elements in the vector
hint	Suggests using specific code. The possible values for the hint argument are described in Hint Arguments.
scaleFactor	Scale factor, refer to Integer Scaling.

Description

The function ippsMean is declared in the ipps.h file. This function computes the mean (average) of the vector pSrc, and stores the result in pMean. The mean of pSrc is defined by the formula:

The hint argument suggests using specific code, either faster but less accurate calculation, or more accurate but slower calculation.

The example below shows how to use the function ippsMean_32f

Return Values

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error when the pMean or pSrc pointer is NULL.
ippStsSizeErr	Indicates an error when len is less than or equal to 0.

Using the ippsMean Function

void mean(void) {
      Ipp32f *x = ippsMalloc_32f(1000), mean;
      int i;
      for(i = 0; i<1000; ++i) x[i] = (float)rand() / RAND_MAX;
      ippsMean_32f(x, 1000, &mean, ippAlgHintFast);
      printf_32f(“mean =”, &mean, 1, ippStsNoErr);
      ippsFree(x);
} 
Output: 
    mean = 0.492591
Matlab* Analog: 
    >> x = rand(1,1000); mean(x)