Re-express a window chosen on primary for another selected layer, as the
same FRACTIONS of each layer's own reference range — the scalar data range
of a colormapped layer, [0, 1] for a direct-colour one. A multi-selection
of layers in different units would otherwise receive the primary's absolute
numbers (a 0–4,000-count window on a 0–1 layer). Falls back to the absolute
window when either reference is unusable.
Re-express a window chosen on
primaryfor another selectedlayer, as the same FRACTIONS of each layer's own reference range — the scalar data range of a colormapped layer,[0, 1]for a direct-colour one. A multi-selection of layers in different units would otherwise receive the primary's absolute numbers (a 0–4,000-count window on a 0–1 layer). Falls back to the absolute window when either reference is unusable.