Standard deviation

Supported Technologies



FwStatus   fwsStdDev_32f ( const Fw32f * pSrcint lenFw32f * pStdDevFwHintAlgorithm hint );
FwStatus   fwsStdDev_64f ( const Fw64f * pSrcint lenFw64f * pStdDev );
FwStatus   fwsStdDev_16s32s_Sfs ( const Fw16s * pSrcint lenFw32s * pStdDevint scaleFactor );
FwStatus   fwsStdDev_16s_Sfs ( const Fw16s * pSrcint lenFw16s * pStdDevint scaleFactor );


hint   Hints whether to choose a fast or accurate computation algorithm.
len   Specifies the number of elements in a buffer.
pSrc   Pointer to a source buffer.
pStdDev   Pointer to the destination buffer that contains the standard deviation of the values in the source buffer.
scaleFactor   Specifies an integer scaling factor for the Sfs operation. The returned result is multiplied by 2^(-scaleFactor).


These functions step through vector elements in a source buffer, calculate the standard deviation of the elements, and write the result to a location specified by a pointer.

The following formula is used.

 StdDev = Sqrt(((n = 0) - (len-1)) Sum(Square(pSrc[n]-pMean))/len-1)

The 16-bit signed versions perform an integer scaling operation on the result.