Heatmap in 1873: Encoding 뿯½ Encoding

In reports, ads and assignments it fits patterns across two categorical axes at once. Skip it when precise lookup of a number, or a rainbow that is not color-blind safe. This page gathers anatomy, fit, craft, failure modes and work / ads / school recipes for Heatmap. When the story is: patterns across two categorical axes at once.

Skip it in cases like: precise lookup of a number, or a rainbow that is not color-blind safe. Toussaint Loua’s 1873 crime tables; later Toussaint/Bertin and 1990s gene arrays color value of a cell in a row-column grid Yes if one claim is visible at a glance in Meta, Google and retail print; otherwise link to a full figure.

Yes for lab reports and poster boards if axes, units and a source line are present. Excel or Google Sheets or PowerPoint; export SVG/PDF. Do not rely on hue alone. Label directly and check greyscale. Heatmap: honour color value of a cell in a row-column grid, and switch when precise lookup of a number, or a rainbow that is not color-blind safe.