Intel® Integrated Performance Primitives Developer Reference

Developer Reference

  • 2021
  • 01/25/2021
  • Public Content
Contents

Ln

Computes natural logarithm of each vector element.

Syntax

IppStatus ippsLn_32f_A11 (const Ipp32f*
pSrc
, Ipp32f*
pDst
, Ipp32s
len
);
IppStatus ippsLn_32f_A21 (const Ipp32f*
pSrc
, Ipp32f*
pDst
, Ipp32s
len
);
IppStatus ippsLn_32f_A24 (const Ipp32f*
pSrc
, Ipp32f*
pDst
, Ipp32s
len
);
IppStatus ippsLn_64f_A26 (const Ipp64f*
pSrc
, Ipp64f*
pDst
, Ipp32s
len
);
IppStatus ippsLn_64f_A50 (const Ipp64f*
pSrc
, Ipp64f*
pDst
, Ipp32s
len
);
IppStatus ippsLn_64f_A53 (const Ipp64f*
pSrc
, Ipp64f*
pDst
, Ipp32s
len
);
IppStatus ippsLn_32fc_A11 (const Ipp32fc*
pSrc
, Ipp32fc*
pDst
, Ipp32s
len
);
IppStatus ippsLn_32fc_A21 (const Ipp32fc*
pSrc
, Ipp32fc*
pDst
, Ipp32s
len
);
IppStatus ippsLn_32fc_A24 (const Ipp32fc*
pSrc
, Ipp32fc*
pDst
, Ipp32s
len
);
IppStatus ippsLn_64fc_A26 (const Ipp64fc*
pSrc
, Ipp64fc*
pDst
, Ipp32s
len
);
IppStatus ippsLn_64fc_A50 (const Ipp64fc*
pSrc
, Ipp64fc*
pDst
, Ipp32s
len
);
IppStatus ippsLn_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 a natural logarithm of each element of
pSrc
 and stores the result in the corresponding element of
pDst
.
For single precision data:
function flavors
ippsLn_32f_A11
and
ippsLn_32cf_A11
 guarantee 11 correctly rounded bits of significand, or at least 3 exact decimal digits;
function flavors
ippsLn_32f_A21
 and
ippsLn_32fc_A21
 guarantee 21 correctly rounded bits of significand, or 4 ulps, or about 6 exact decimal digits;
function flavors
ippsLn_32f_A24
 and
ippsLn_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
ippsLn_64f_A26
 and
ippsLn_64fc_A26
 guarantee 26 correctly rounded bits of significand, or 6.7E+7 ulps, or approximately 8 exact decimal digits;
function flavors
ippsLn_64f_A50
 and
ippsLn_64fc_A50
 guarantee 50 correctly rounded bits of significand, or 4 ulps, or approximately 15 exact decimal digits;
function flavors
ippsLn_64f_A53
 and
ippsLn_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] = log
e
(
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.
IppStsDomain
In real functions, indicates a warning that the argument is out of the function domain, that is, at least one of the elements of
pSrc
 is less than 0.
IppStsSingularity
In real functions, indicates a warning that the argument is the singularity point, that is, at least one of the elements of
pSrc
 is equal to 0.

Example

The example below shows how to use the function
ippsLn
. 
IppStatus ippsLn_32f_A21_sample(void)
{
const Ipp32f x[4] = {0.188, 3.841, 5.363, 5.755};
Ipp32f      			y[4];
	IppStatus st = ippsLn_32f_A21( x, y, 4 );
	printf(" ippsLn_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:
 ippsLn_32f_A21: 
 x = 0.188 3.841 5.363 5.755
 y = -1.670 1.346 1.680 1.750

Product and Performance Information

1

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