Style the map
Goal: get a publication-worthy view — choose a colormap, set data limits, mask values, pick a scale mode, and add geographic context.
Choose and tune a colormap
| Task | Do this |
|---|---|
| Cycle built-in palettes | c or the sidebar palette button |
| Reverse the palette | v |
Add custom .ncmap files | put them in the working directory, or set NCVIEW_COLORMAPS=/path/to/maps (NCVIEW_LIB_DIR and NCVIEWBASE are also searched, including share/ncview/colormaps) |
Built-ins: Viridis, Plasma, Turbo, Inferno, Magma, Cividis, Cool, Warm,
Cubehelix, Spectral. Malformed .ncmap files are ignored at startup, so a bad
file can never break the viewer.
Set data limits
| Task | Do this |
|---|---|
| Automatic limits from the displayed slice | a |
| Type exact min/max | l — type into a field, Tab switches fields, Enter applies, Esc cancels |
| Mask everything outside a range | f |
| Linear ↔ logarithmic color scale | s |
| Scale scope: current-slice vs unzoomed-global | z or the sidebar scale-scope button |
| Reset zoom | r |
Manual limits always take precedence over either automatic mode. _FillValue
and missing values stay masked automatically regardless of your settings.
Zoom and pan
- Drag across the map to zoom to a rectangle.
- Drag a zoomed map to pan, or use
Shift+arrows. Shift-drag while already zoomed zooms again inside the current view.rreturns to the full map.
Zooming changes which values the current-slice automatic limits see; switch
the scope to global with z if you want colors to stay stable while zooming.
Geographic backdrop
Press b to layer a D3-inspired ocean, graticule, and filled Natural Earth
land backdrop beneath the raster. Valid data composites on top; fill/missing
cells reveal the geography. It is a presentation aid only — it never
changes data values or replaces a dataset-provided land/sea mask.
Select coastline detail with NCVIEW_LAND_DETAIL=auto|110m|50m|10m
(110m is the fast default once enabled; the overlay starts disabled so first
render stays light).
Export the result
Press e to write the current variable/time/depth slice as PNG + SVG + JSON.
See Compare and export.