Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference
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Ln
Computes the natural logarithm of each element of a vector.
Syntax
IppStatus ippsLn_32f(const Ipp32f* pSrc, Ipp32f* pDst, int len);
IppStatus ippsLn_64f(const Ipp64f* pSrc, Ipp64f* pDst, int len);
IppStatus ippsLn_16s_Sfs(const Ipp16s* pSrc, Ipp16s* pDst, int len, int scaleFactor);
IppStatus ippsLn_32s_Sfs(const Ipp32s* pSrc, Ipp32s* pDst, int len, int scaleFactor);
IppStatus ippsLn_16s_ISfs(Ipp16s* pSrcDst, int len, int scaleFactor);
IppStatus ippsLn_32s_ISfs(Ipp32s* pSrcDst, int len, int scaleFactor);
IppStatus ippsLn_32f_I(Ipp32f* pSrcDst, int len);
IppStatus ippsLn_64f_I(Ipp64f* pSrcDst, int len);
Include Files
ipps.h
Domain Dependencies
Headers: ippcore.h, ippvm.h
Libraries: ippcore.lib, ippvm.lib
Parameters
| pSrc | Pointer to the source vector. | 
| pDst | Pointer to the destination vector. | 
| pSrcDst | Pointer to the source and destination vector for the in-place operation. | 
| len | Number of elements in the vector | 
| scaleFactor | Scale factor, refer to Integer Scaling. | 
Description
This function computes the natural logarithm of each element of the vector pSrc and stores the result in pDst as given by
pDst[n] = loge (pSrc[n])
The in-place flavors of ippsLn compute the natural logarithm of each element of the vector pSrcDst and store the result in pSrcDst as given by
pSrcDst[n] = loge (pSrcDst[n])
If the function ippsLn encounters a zero or negative value in the input, it returns a warning status and continues execution with the corresponding result value (see appendix A "Handling of Special Cases" for more information).
Return Values
| ippStsNoErr | Indicates no error. | 
| ippStsNullPtrErr | Indicates an error when the pSrc, pDst, or pSrcDst pointer is NULL. | 
| ippStsSizeErr | Indicates an error when len is less than or equal to zero. | 
| ippStsLnZeroArg | Indicates a warning for zero-valued input vector elements. | 
| ippStsLnNegArg | Indicates a warning for negative input vector elements. | 
Example
Ln:
/*******************************************************************************
* Copyright 2015 Intel Corporation.
*
*
* This software and the related documents are Intel copyrighted materials, and your use of them is governed by
* the express license under which they were provided to you ('License'). Unless the License provides otherwise,
* you may not use, modify, copy, publish, distribute, disclose or transmit this software or the related
* documents without Intel's prior written permission.
* This software and the related documents are provided as is, with no express or implied warranties, other than
* those that are expressly stated in the License.
*******************************************************************************/
#include <stdio.h>
#include "ipp.h"
/* Next two defines are created to simplify code reading and understanding */
#define EXIT_MAIN exitLine:                                  /* Label for Exit */
#define check_sts(st) if((st) != ippStsNoErr) goto exitLine; /* Go to Exit if Intel(R) Integrated Performance Primitives (Intel(R) IPP) function returned status different from ippStsNoErr */
/* Results of ippMalloc() are not validated because Intel(R) IPP functions perform bad arguments check and will return an appropriate status  */
int main()
{
    int len = 32;
    int i;
    Ipp16s *pSrc = ippsMalloc_16s(len * sizeof(Ipp16s));
    Ipp16s *pDst = ippsMalloc_16s(len * sizeof(Ipp16s));
    IppStatus status;
    int scale = 0;  //without scaling
    printf("\n\nSource vector\n");
    for (i = 0; i < len; i++)
    {
        pSrc[i] = 2 + i;
        printf("%d; ", pSrc[i]);
    }
    check_sts(status = ippsLn_16s_Sfs(pSrc, pDst, len, scale));
    printf("\n\nResult\n");
    for (i = 0; i < len; i++) printf("%d; ", pDst[i]);
    printf("\n\n");
EXIT_MAIN
    ippsFree(pSrc);
    ippsFree(pDst);
    printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status));
    return (int)status;
}Ln_I:
/*******************************************************************************
* Copyright 2015 Intel Corporation.
*
*
* This software and the related documents are Intel copyrighted materials, and your use of them is governed by
* the express license under which they were provided to you ('License'). Unless the License provides otherwise,
* you may not use, modify, copy, publish, distribute, disclose or transmit this software or the related
* documents without Intel's prior written permission.
* This software and the related documents are provided as is, with no express or implied warranties, other than
* those that are expressly stated in the License.
*******************************************************************************/
#include <stdio.h>
#include "ipp.h"
/* Next two defines are created to simplify code reading and understanding */
#define EXIT_MAIN exitLine:                                  /* Label for Exit */
#define check_sts(st) if((st) != ippStsNoErr) goto exitLine; /* Go to Exit if Intel(R) Integrated Performance Primitives (Intel(R) IPP) function returned status different from ippStsNoErr */
/* Results of ippMalloc() are not validated because Intel(R) IPP functions perform bad arguments check and will return an appropriate status  */
int main()
{
    int len = 32;
    int i;
    Ipp16s *pSrcDst = ippsMalloc_16s(len * sizeof(Ipp16s));
    IppStatus status;
    int scale = 0;  //without scaling
    printf("\n\nSource vector\n");
    for (i = 0; i < len; i++)
    {
        pSrcDst[i] = 2 + i;
        printf("%d; ", pSrcDst[i]);
    }
    check_sts(status = ippsLn_16s_ISfs(pSrcDst, len, scale));
    printf("\n\nResult\n");
    for (i = 0; i < len; i++) printf("%d; ", pSrcDst[i]);
    printf("\n\n");
EXIT_MAIN
    ippsFree(pSrcDst);
    printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status));
    return (int)status;
}