Arctan
Calculates the arc tangent value of each element in a vector.
The calculation formula is: pDst[n]=tan-1(pSrc[n]), where n ranges [0, len).
The function interface declaration is as follows:
- Operations on floating-point numbers:
HmppResult HMPPS_Arctan_32f(const float* src, float* dst, int32_t len);
HmppResult HMPPS_Arctan_64f(const double* src, double* dst, int32_tlen);
- In-place operations on floating-point numbers:
HmppResult HMPPS_Arctan_32f_I(float* srcDst, int32_tlen);
HmppResult HMPPS_Arctan_64f_I(double* srcDst, int32_tlen);
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 in-place operation vector |
The value cannot be NULL. |
Input/Output |
len |
Vector length |
(0, INT_MAX] |
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. |
Example
#define BUFFER_SIZE_T 10
void ArctanExample(void)
{
float src[BUFFER_SIZE_T] = {4.52, 5.92, 5.16, 6.15, 8.17, 9.93, 6.04, 11.17, 2.79, 3.58};
float dst[BUFFER_SIZE_T];
(void)HMPPS_Zero_32f(dst, BUFFER_SIZE_T); //Initialize all elements of dst to 0.
HmppResult result = HMPPS_Arctan_32f(src, dst, BUFFER_SIZE_T);
printf("result = %d\n", result);
if (result != HMPP_STS_NO_ERR) {
return;
}
printf("dst =");
for (int i = 0; i < BUFFER_SIZE_T; i++) {
printf(" %.2f", dst[i]);
}
printf("\n");
}
Output:
result = 0 dst = 1.35 1.40 1.38 1.41 1.45 1.47 1.41 1.48 1.23 1.30