Understanding how an analysis result evolves over time is often essential. If the result is a single numerical value, you can visualize its changes using the Instrument values log, which plots the value as a function of time.

However, when the result is a value array - such as an FFT sequence, octave plot or autocorrelation result - you can track its changes over time by displaying it in a 3D graphics or spectrogram. In these views, every time the input value array updates, a new column representing its values is added. This feature works not only with FFTs  but also with any signal or analysis result in SIGVIEW.

To use this feature, choose one of the following options from the main menu:

  • “Signal tools > Track changes in 3D graphics”
  • “Signal tools > Track changes in spectrogram view”

Before the visualization begins, you’ll be prompted to define how many columns (i.e., how many previous signal states) the graphic should store.

Each time the source signal updates:

  • A new column with the current signal values is added.
  • The oldest column is removed to maintain the defined column count.

Axis Behavior

  • X-Axis: Initially labeled as “Change,” it represents the sequence of updates (e.g., 0, 1, 2, 3…).
  • Y-Axis: Uses the same units as the original signal’s X-axis.

After a few updates, SIGVIEW attempts to automatically assign meaningful time values to the X-axis by analyzing the source signal’s properties. If the X-values are evenly spaced (equidistant), they will be used. Otherwise, the axis will revert to the default “Change” index labeling.

Important Note

If the length of the original signal changes (e.g., due to zooming in or out), further updates will not be added to the 3D graphic until the signal is returned to its previous length. This ensures consistent visualization dimensions.

For more information see: Track analysis results through time as 3D graphics and Basic 3D operations.