Spectral Domain Plots in Transient (FFT)
When plotting in the spectral domain, you must specify the parameters for the Fast Fourier Transform (FFT). The FFT function used by Maxwell uses windowing; therefore, the user must enter a start and stop time within which the data is periodic.
To enter the FFT parameters:
- In the Report window, be sure the Domain is set to Spectral.
- In the Context section of the reporter dialog box, click FFT Options.
The FFT Options dialog appears.
- Enter the Start Time for the window using the drop-down menu.
- Enter the End Time using the drop-down menu.
- Enter the Window Type using the drop-down menu.
The samples and number of points are calculated based on the chosen start and end values. The signal must be periodic during the time interval chosen or an error will result.