The routine local_resolution is a tool for creating a local resolution map showing the local resolution of a cryo-EM map and having the same gridding as the cryo-EM map
Local resolution is calculated in small boxes cut out from the cryo-EM map, where the density near the edges of each box is masked so that it gradually diminishes to zero at the edges. Then the values of local resolution are smoothed and placed at grid points of a full-size map matching the original map.
The local resolution map can be used to color a map in display programs such as ChimeraX. In ChimeraX you can simply load in your original map and the local resolution map and then specify:
color sample #1 map #2 palette rainbow
to color map #1 based on the resolution values in map #2.
The basic inputs to local_resolution are:
Two unmasked half-maps
Optional inputs are:
nominal resolution
You can use local_resolution to get the local resolution in a cryo-EM map:
phenix.local_resolution half_map_A.mrc half_map_B.mrc
If the half-maps are not actually independent the procedure will not work well
{{phil:phenix.programs.local_resolution}}