Developer Reference

  • 2020
  • 10/21/2020
  • Public Content
Contents

Atan

Computes inverse tangent of each vector element.

Syntax

IppStatus ippsAtan_32f_A11 (const Ipp32f*
pSrc
, Ipp32f*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_32f_A21 (const Ipp32f*
pSrc
, Ipp32f*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_32f_A24 (const Ipp32f*
pSrc
, Ipp32f*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_64f_A26 (const Ipp64f*
pSrc
, Ipp64f*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_64f_A50 (const Ipp64f*
pSrc
, Ipp64f*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_64f_A53 (const Ipp64f*
pSrc
, Ipp64f*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_32fc_A11 (const Ipp32fc*
pSrc
, Ipp32fc*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_32fc_A21 (const Ipp32fc*
pSrc
, Ipp32fc*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_32fc_A24 (const Ipp32fc*
pSrc
, Ipp32fc*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_64fc_A26 (const Ipp64fc*
pSrc
, Ipp64fc*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_64fc_A50 (const Ipp64fc*
pSrc
, Ipp64fc*
pDst
, Ipp32s
len
);
IppStatus ippsAtan_64fc_A53 (const Ipp64fc*
pSrc
, Ipp64fc*
pDst
, Ipp32s
len
);
Include Files
ippvm.h
Domain Dependencies
Headers:
ippcore.h
Libraries:
ippcore.lib
Parameters
pSrc
Pointer to the source vector.
pDst
Pointer to the destination vector.
len
Number of elements in the vectors.
Description
This function computes the inverse tangent of each element of
pSrc
, and stores the result in the corresponding element of
pDst
.
For single precision data:
function flavors
ippsAtan_32f_A11
and
ippsAtan_32cf_A11
guarantee 11 correctly rounded bits of significand, or at least 3 exact decimal digits;
function flavors
ippsAtan_32f_A21
and
ippsAtan_32fc_A21
guarantee 21 correctly rounded bits of significand, or 4 ulps, or about 6 exact decimal digits;
function flavors
ippsAtan_32f_A24
and
ippsAtan_32fc_A24
guarantee 24 correctly rounded bits of significand, including the implied bit, with the maximum guaranteed error within 1 ulp.
For double precision data:
function flavors
ippsAtan_64f_A26
and
ippsAtan_64fc_A26
guarantee 26 correctly rounded bits of significand, or 6.7E+7 ulps, or approximately 8 exact decimal digits;
function flavors
ippsAtan_64f_A50
and
ippsAtan_64fc_A50
guarantee 50 correctly rounded bits of significand, or 4 ulps, or approximately 15 exact decimal digits;
function flavors
ippsAtan_64f_A53
and
ippsAtan_64fc_A53
guarantee 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] = atan(
pSrc
[n])
,
0 ≤ n <
len
.
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.

Example

The example below shows how to use the function
ippsAtan
.
IppStatus ippsAtan_32f_A21_sample(void)
{
const Ipp32f x[4] = {0.994, 0.999, 0.223, -0.215};
Ipp32f y[4];
IppStatus st = ippsAtan_32f_A21( x, y, 4 );
printf(" ippsAtan_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:
ippsAtan_32f_A21:
x = 0.994 0.999 0.223 -0.215
y = 0.782 0.785 0.219 -0.212

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.