167915.fig.002a
(a)
167915.fig.002b
(b)
Figure 2: Empirical spatial distribution of probe residuals in original and corrected data. Mapping probe residuals back to their originating physical locations and displaying them as a heat map reveals a variety of spatial artefacts in (a) original data: horizontal stripes (all arrays), a large region of positive residuals (GSE2189, left), and a small region of negative residuals (spike-in, bottom right); (b) after correction ( ), all of these artefacts appear to have been eliminated or greatly attenuated. Non-PM locations (MM and control probes) are coloured in white.