Spectrogram Layer Control

This control is experimental. It is missing some important features, and the interface may be changed in a future version.

The Spectrogram Layer Control (

) plots a spectrum at successive (usually, but not necessarily, regularly-spaced) points in a time series. It is only available for the Time Plot Window; you can add one of these controls to the stack by using the Add Spectrogram Control (

) button in the control panel toolbar, or the corresponding item in the Layers menu.

This control has only one layer-specific tab, Data, described below. The Zone tab is described in Appendix A.4.13.1.

Data Tab

Spectrogram control Data tab

The Data tab allows you to specify which values from a table will generate a spectrogram. It has the following fields:

Table: The table supplying the data.
Time: A table column or expression giving the epoch coordinate at which spectra are located. This should normally be a time-typed column; if it is simply of numeric type it will be interpreted as seconds since 1 Jan 1970.
Spectrum: An array-valued table column giving the spectral data.
TimeWidth: A table column or expression (variable or constant) giving the temporal coverage of a plotted spectrum. If not filled in, it is assumed to be the most common (median) difference between time points.
Row Subset: The subset for which the spectrum should be plotted. To plot multiple subsets (not usually useful with this kind of plot) you would need multiple spectrogram layer controls in the stack.

To control the colour map used to represent the spectral values, use the Aux

fixed control.

A.4.4.7 Spectrogram Layer Control