Section 25.2.1.12.2. Interactive contouring or mask editing

The interactive program MAPVIEW can be used to examine contoured electron-density or Patterson maps, as well as to examine, create or edit solvent or averaging masks. Either full-cell FSFOUR maps or submaps (including skewed submaps) can be used, although only from the former can any arbitrary region be obtained and reordered interactively. The mask creation and editing functions have been described earlier. The program is very useful for Patterson analysis, evaluation of phasing results and to help decide which region is appropriate for isolating a molecule for use in model building. It is usually crucial for construction of averaging masks, but is also useful for examining or editing other masks.