FHT
Advanced Analysis Library Only
AnalysisLibErrType FHT (double array[], ssize_t numberOfElements);
Purpose
Calculates the fast Hartley transform (FHT) using the following formula:
| where | Xk is the kth point of the FHT |
| and cas(k) = cos(k) + sin(k) |
FHT can perform the operation in place and overwrite the input array.
 |
Note This function requires the size of the input data to be a power of two. |
Example Code
/* Generate an array with random numbers and calculate its fast Hartley transform. */
double x[256];
n;
n = 256;
Uniform (n, 17, x);
FHT (x, n);
Parameters
| Input | ||
| Name | Type | Description |
| numberOfElements | ssize_t | Number of elements in the input array. Default Value: 1024. Valid Values: powers of 2. |
| Output | ||
| Name | Type | Description |
| array | double [] | On input, the values used to compute the FHT. On output, the fast Hartley transform. This operation is performed in place, meaning the values in this array are overwritten. |
Return Value
| Name | Type | Description |
| status | AnalysisLibErrType | A value that specifies the type of error that occurred. Refer to analysis.h for definitions of these constants. |
Additional Information
Library: Advanced Analysis Library
Include file: analysis.h
LabWindows/CVI compatibility: LabWindows/CVI 3.1 and later