Electron density maps: Difference between revisions

Electron density values fill 3-dimensional space of the map (see this [http://www.bioinformatics.org/molvis/edm/ interactive visualization]). The term "map" is historical; the three-dimensional electron density was plotted on several pages, slice-by-slice, with contour lines corresponding to the value of the density at that location. These plots were called a map, in reference to topographical maps. The standard deviation of all density values, ''sigma'', is used to describe the strength of features in a map (e.g. a "3 sigma peak" is a feature that has a density value higher than three sigma over the average value).