Advanced Analysis Library Only
AnalysisLibErrType CrossSpectrum (double xArray[], double yArray[], int numberOfElements, double realSxy[], double imaginarySxy[]);
Calculates the double-sided cross power spectrum, Sxy, of the input sequences X and Y according to the following formula:
where FFT*[X] is the complex conjugate of FFT[X] and n is the number of points in the arrays.
The input sequences are copied to internal buffers and zero-padded to numberOfElements samples before the FFTs are computed. The output arrays are the real and imaginary parts of the cross spectrum CrossSpectrum.
| Input | ||
| Name | Type | Description |
| xArray | double-precision array | Time-domain signal X. |
| yArray | double-precision array | Time-domain signal Y. |
| numberOfElements | integer | Number of elements in the input arrays. |
| Output | ||
| Name | Type | Description |
| realSxy | double-precision array | Real part of the double-sided cross power spectrum between signals X and Y. The size of this array must be at least numberOfElements. |
| imaginarySxy | double-precision array | Imaginary part of the double-sided cross power spectrum between signals X and Y. The size of this array must be at least numberOfElements. |
| Name | Type | Description |
| status | AnalysisLibErrType | A value that specifies the type of error that occurred. Refer to analysis.h for definitions of these constants. |