Waterfall & Spectrogram Graphs
Overview
Waterfall and Spectrogram visualizations display 1Dts (spectrum time-series) data, showing how spectral signatures evolve over time - for example, an EELS spectrum series acquired during an in-situ heating experiment.
Creating a Waterfall / Spectrogram Panel
Drag a 1Dts signal from the Data tab onto an empty canvas area. Nexus detects the signal type and automatically creates a Waterfall Graph panel.
Display Layout
The spectrogram renders the data as a 2-D colour matrix:
| Axis | Represents |
|---|---|
| X | Time (stacked spectra) |
| Y | Spectrum index (energy / frequency bins) |
| Colour | Intensity - blue for low values, red for high values |
Pan and Zoom
| Action | Effect |
|---|---|
| Ctrl + scroll wheel | Zoom in / out around the mouse cursor |
| Click + drag to draw a box | Zoom into the selected region (drag-zoom) |
| Shift + click + drag | Pan the view while keeping the current zoom level |
| Maximize button | Reset zoom to show full data range |
Timeline Cursor
A vertical line indicates the current timeline position (time on the X axis), showing which spectrum corresponds to the selected time. Moving the main timeline scrubber updates this cursor in real time.
Colour Scale
The intensity-to-colour mapping adjusts automatically to the data range. At the moment, the WaterfallChart does not render a separate on-screen colour-scale legend; interpretation relies on the consistent blue-to-red mapping across datasets.
Use Cases
- EELS time-series - track chemical changes (e.g. Ti → TiO₂ oxidation) by observing edge shifts over time.
- EDS spectra - monitor elemental composition evolution during heating.
- Raman series - observe phase transitions through peak shifts.