Ln
Calculates the natural logarithm of each element in a vector.
The function interface declaration is as follows:
- Operations on floating-point numbers:
HmppResult HMPPS_Ln_32f(const float* src, float* dst, int32_t len);
HmppResult HMPPS_Ln_64f(const double* src, double* dst, int32_t len);
- In-place operations on floating-point numbers:
HmppResult HMPPS_Ln_32f_I(float* srcDst, int32_t len);
HmppResult HMPPS_Ln_64f_I(double* srcDst, int32_t len);
- Operations on integers with scaling:
HmppResult HMPPS_Ln_16s_S(const int16_t* src, int16_t* dst, int32_t len, double scale);
HmppResult HMPPS_Ln_32s_S(const int32_t* src, int32_t* dst, int32_t len, double scale);
- In-place operations on integers with scaling:
HmppResult HMPPS_Ln_16s_IS(int16_t* srcDst, int32_t len, double scale);
HmppResult HMPPS_Ln_32s_IS(int32_t* srcDst, int32_t len, double scale);
Parameters
Parameter |
Description |
Value Range |
Input/Output |
|---|---|---|---|
src |
Pointer to the source vector |
The value cannot be NULL. |
Input |
dst |
Pointer to the destination vector |
The value cannot be NULL. |
Output |
srcDst |
Pointer to the source vector for in-place operations |
The value cannot be NULL. |
Input/Output |
len |
Vector length |
(0, INT_MAX] |
Input |
scale |
Scale factor |
scale = 2^n, where n is an integer. The value is within (0, INF). |
Input |
Return Value
- Success: HMPP_STS_NO_ERR
- Failure: An error code is returned.
Error Codes
Error Code |
Description |
|---|---|
HMPP_STS_NULL_PTR_ERR |
The value of src, dst, or srcDst is NULL. |
HMPP_STS_SIZE_ERR |
The value of len is less than or equal to 0. |
HMPP_STS_LN_NEG_ARG |
The antilogarithm is a negative number. |
HMPP_STS_LN_ZERO_ARG |
The antilogarithm is 0. |
HMPP_STS_SCALE_ERR |
The value of scale is not within the range (0, INF) or is NaN. |
HMPP_STS_SINGULARITY |
At least one element in src is equal to 0. |
HMPP_STS_DOMAIN |
At least one element in src is less than 0. |
Example
#define BUFFER_SIZE_T 10
void LnExample(void)
{
float src[BUFFER_SIZE_T] = {6.17, 6.13, 0.70, 9.23, 3.71, 6.13, 0.90, 10.21, 0.70, 1.12};
float dst[BUFFER_SIZE_T];
(void)HMPPS_Zero_32f(dst, BUFFER_SIZE_T); //Initialize all elements of dst to 0.
HmppResult result = HMPPS_Ln_32f(src, dst, BUFFER_SIZE_T);
printf("result = %d\n", result);
if (result != HMPP_STS_NO_ERR) {
return;
}
printf("dst =");
for (int32_t i = 0; i < BUFFER_SIZE_T; i++) {
printf(" %.2f", dst[i]);
}
printf("\n");
}
Output:
result = 0 dst = 1.82 1.81 -0.36 2.22 1.31 1.81 -0.11 2.32 -0.36 0.11