FFTShift
Shifts the zero-frequency point to the center of the spectrum. For one-dimensional signals, the left part and right part of The value of group are exchanged.
The function interface declaration is as follows:
Operations on floating point numbers:
HmppResult HMPPS_FFTShift_32f(const float *src, float *dst, int32_t len);
HmppResult HMPPS_FFTShift_64f(const double *src, double *dst, int32_t len);
HmppResult HMPPS_FFTShift_32fc(const Hmpp32fc *src, Hmpp32fc *dst, int32_t len);
HmppResult HMPPS_FFTShift_64fc(const Hmpp64fc* src, Hmpp64fc* dst, int32_t len);
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 |
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 or dst is NULL. |
HMPP_STS_SIZE_ERR |
The value of len is less than or equal to 0. |
Example
#define BUFFER_SIZE_T 10
void FFTShift_Example(void)
{
float src[BUFFER_SIZE_T] = {1.64, 1.63, -1.09, 0.71, -3.20, -0.43, 0.41, -4.83, 5.36, -4.40};
float dst[BUFFER_SIZE_T];
int32_t i;
HmppResult result = HMPPS_FFTShift_32f(src, dst, BUFFER_SIZE_T);
printf("result = %d \ndst =", result);
for (i = 0; i < BUFFER_SIZE_T; i++) {
printf("%.2f ", dst[i]);
}
}
Output:
result = 0 dst = -0.43 0.41 -4.83 5.36 -4.40 1.64 1.63 -1.09 0.71 -3.20