pace.cell_contamination

pace.cell_contamination(fit)

Per cell: the contamination loading, and the fraction it explains.

Read the fraction rather than the loading. The ambient field is cross-cell-type, so a cell with no differently-typed neighbour inside the technical kernel has no ambient signal at all; its loading is unidentified and shrinks to the prior mean, giving every such cell the same apparently middling value. The fraction reports those cells as zero, correctly.