nc2 2.0.0

Lightweight NetCDF viewer with detached plot windows, GIF export, and full matplotlib customization.

Fast, versatile NetCDF viewer built for scientists.
Replaces ncview and Panoply with a lightweight, offline-capable tool that runs anywhere Python does.

Install

pip install nc2

Requires Python 3.8+. Cartopy is needed for map projections (optional for non-geographic data).

Usage

nc2                          # launch empty, open file from menu
nc2 data.nc                  # open a file directly
python -m nc2 data.nc4       # alternate invocation

Features

• Spatial plots -- pcolormesh, contourf, contour, imshow, quiver, streamplot
• Vertical sections -- depth vs. lat/lon cross-sections
• Timeseries -- click any point to extract temporal evolution
• Depth profiles -- vertical structure at a point
• GIF export -- animate over time with configurable FPS and frame range
• Full matplotlib API -- normalization (log, symlog, power), interpolation, alpha, colorbar controls, contour styling, quiver/streamplot parameters
• 182 colormaps -- every registered matplotlib colormap at runtime
• Cartopy projections -- PlateCarree, Mercator, Robinson, Orthographic, and more
• Flexible dimensions -- auto-detects time/depth/lat/lon, manual override for non-standard files
• Extra dimensions -- unassigned dims get their own sliders automatically
• Playback -- animate through time with loop/bounce/once modes and speed control
• Detached windows -- each plot is an independent matplotlib window with toolbar
• Batch export -- export all frames as individual images
• Performance -- LRU slice cache, lazy coordinate loading, threaded I/O

Architecture

nc2/
  __main__.py      Entry point
  app.py           Control panel (tkinter + ttkbootstrap)
  dataset.py       NetCDF wrapper, dimension classification
  slicer.py        Data extraction with caching
  cache.py         Thread-safe LRU cache
  playback.py      Animation controller
  export.py        GIF/image/batch export
  constants.py     Configuration defaults, heuristics
  widgets.py       Custom widgets and dialogs
  plots/
    config.py      PlotConfig dataclass
    manager.py     Window lifecycle management
    spatial.py     2D map/field plots
    section.py     Cross-section plots
    series.py      Timeseries and depth profiles

Dependencies

Package	Purpose
numpy	Array operations
matplotlib	Plotting engine
netCDF4	File I/O
cartopy	Map projections and features
ttkbootstrap	GUI styling
Pillow	Image handling
imageio	GIF assembly

License

GPL-3.0. Copyright (c) 2024 Rhett R. Adam.