9 Displaying a Sequence of Slices

This network is a modification of the network for displaying a two-dimensional slice through a data cube parallel to two of the axes (see Section 8). Instead of displaying a single slice it generates an animation showing successive slices ‘sweeping’ through the data cube. Note that, as before, the colour table for converting data values into displayed colours is derived from the range of values in the entire data cube, not just the current slice being plotted, in order to facilitate visualisation as the current slice sweeps through the data cube.

9.1 Use

The network is shown in Figure 12.

Figure 12: Network to display a sequence of slices in a data cube.

• To specify the data cube to be read double-click on the ‘Import’ module and follow the instructions in Section 4.1.
• To specify the axis to which the slice is perpendicular double-click on the ‘Integer’ module at the top of the network. The permitted values are 0, 1 and 2 for the $x,y$ and $z$ axes respectively.
• To specify the range of slices to be shown double-click on the ‘Sequencer’ module. A control panel with controls similar to (and corresponding functions to) the buttons on a cassette tape deck appears. Click on the ellipsis (‘…’) button and a further window appears allowing you to specify the first and last slice to be extracted (and the increment between slices). For a cube with $n$ elements along the chosen axis the permitted values are 0 to $n-1$.

  Finally, once you have chosen the required range, click on the play button (‘$⊳$’) in the original ‘Sequencer’ window.

9.2 Notes

This network is identical to network slice.net for displaying a single slice except that the right-hand of the two ‘Integer’ modules in slice.net, which specified the requested slice, has been replaced with the ‘Sequencer’ module.