Computes the error function value.
Syntax
IppStatus ippsErf_32f_A11 (const Ipp32f* pSrc, Ipp32f* pDst, Ipp32s len);
IppStatus ippsErf_32f_A21 (const Ipp32f* pSrc, Ipp32f* pDst, Ipp32s len);
IppStatus ippsErf_32f_A24 (const Ipp32f* pSrc, Ipp32f* pDst, Ipp32s len);
IppStatus ippsErf_64f_A26 (const Ipp64f* pSrc, Ipp64f* pDst, Ipp32s len);
IppStatus ippsErf_64f_A50 (const Ipp64f* pSrc, Ipp64f* pDst, Ipp32s len);
IppStatus ippsErf_64f_A53 (const Ipp64f* pSrc, Ipp64f* pDst, Ipp32s len);
Parameters
pSrc |
Pointer to the source vector. |
pDst |
Pointer to the destination vector. |
len |
Number of elements in the vectors. |
Description
The function ippsErf is declared in the ippvm.h file. This function computes the error function value for each element of pSrc and stores the result in the corresponding element of pDst.
For single precision data:
function flavor ippsErf_32f_A11 guarantees 11 correctly rounded bits of significand, or at least 3 exact decimal digits;
function flavor ippsErf_32f_A21 guarantees 21 correctly rounded bits of significand, or 4 ulps, or about 6 exact decimal digits;
function flavor ippsErf_32f_A24 guarantees 24 correctly rounded bits of significand, including the implied bit, with the maximum guaranteed error within 1 ulp.
For double precision data:
function flavor ippsErf_64f_A26 guarantees 26 correctly rounded bits of significand, or 6.7E+7 ulps, or approximately 8 exact decimal digits;
function flavor ippsErf_64f_A50 guarantees 50 correctly rounded bits of significand, or 4 ulps, or approximately 15 exact decimal digits;
function flavor ippsErf_64f_A53 guarantees 53 correctly rounded bits of significand, including the implied bit, with the maximum guaranteed error within 1 ulp.
The computation is performed as follows:
pDst[n] = erf(pSrc[n]), 0 ≤ n <
len, where 
The example below shows how to use the function ippsErf.
Return Values
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error when pSrc or pDst pointer is NULL. |
ippStsSizeErr |
Indicates an error when len is less than or equal to 0. |
Using ippsErf Function
IppStatus ippsErf_32f_A21_sample(void)
{
const Ipp32f x[4] = {-0.982, 0.838, -0.448, -0.454};
Ipp32f y[4];
IppStatus st = ippsErf_32f_A21( x, y, 4 );
printf(" ippsErf_32f_A21:\n");
printf(" x = %.3f %.3f %.3f %.3f \n", x[0], x[1], x[2], x[3]);
printf(" y = %.3f %.3f %.3f %.3f \n", y[0], y[1], y[2], y[3]);
return st;
}
Output results:
ippsErf_32f_A21:
x = -0.982 0.838 -0.448 -0.454
y = -0.835 0.764 -0.474 -0.479