CLI_interpolate

Interpolation CLI (experimental)

interpolate is registered, but is not operational in NES 1.3.5. The CLI dispatcher calls handlers with filtered keyword arguments, whereas interpolate(args) requires a Namespace. Other inconsistencies include source/output versus input_file/output_file, destination validation, missing LCC/Mercator parameter names, and API call signatures. The options below describe the parser, not a working end-to-end command.

-i and -o are required. Exactly one of --destination or --projection is required. Horizontal and vertical options must not be mixed.

Argument	Parser description
-i, --input_file	Path to source NetCDF file
-o, --output_file	Path to output NetCDF file
--axis	Interpolation axis (default: horizontal)
-d, --destination	Path to destination grid NetCDF file
--projection	Projection type to generate destination grid (e.g. regular, rotated, lcc)
--kind	Interpolation method for horizontal axis
--n-neighbours	Number of neighbors (NearestNeighbour)
--flux	Treat variables as fluxes (Conservative only)
--keep-nan	Keep NaN values after interpolation
--fix-border	Fix border effects (NearestNeighbour only)
--weight-matrix-path	Path to weight matrix file
--only-create-wm	Only generate weight matrix
--to-providentia	Format output for Providentia
--method	Interpolation method for vertical axis (e.g. linear)
--extrapolate	Allow extrapolation in vertical interpolation
--lat_orig	Latitude origin (regular/global)
--lon_orig	Longitude origin (regular/global)
--inc_lat	Latitude increment (regular/global)
--inc_lon	Longitude increment (regular/global)
--n_lat	Number of latitude points (regular/global)
--n_lon	Number of longitude points (regular/global)
--centre_lat	Rotated pole latitude (rotated)
--centre_lon	Rotated pole longitude (rotated)
--west_boundary	Western boundary (rotated)
--south_boundary	Southern boundary (rotated)
--inc_rlat	Latitude increment (rotated)
--inc_rlon	Longitude increment (rotated)
--parent_grid_path	Path to parent grid NetCDF (rotated_nested)
--parent_ratio	Parent ratio (rotated_nested)
--i_parent_start	Parent grid i index start (rotated_nested)
--j_parent_start	Parent grid j index start (rotated_nested)
--n_rlat	Number of lat points (rotated_nested)
--n_rlon	Number of lon points (rotated_nested)
--lat_1	First standard parallel (LCC projection)
--lat_2	Second standard parallel (LCC projection)
--lon_0	Central meridian (LCC projection)
--x_0	False easting (LCC projection)
--y_0	False northing (LCC projection)
--dx	Grid spacing in x direction (LCC projection)
--dy	Grid spacing in y direction (LCC projection)
--nx	Number of grid points in x (LCC projection)
--ny	Number of grid points in y (LCC projection)
--lat_ts	Latitude of true scale (Mercator projection)

Python alternative

from nes import open_netcdf

source = open_netcdf("source.nc")
source.load()
destination = open_netcdf("destination.nc")
result = source.interpolate_horizontal(destination, kind="NearestNeighbour", n_neighbours=4)
result.to_netcdf("interpolated.nc")
source.close()
destination.close()

For conservative interpolation use kind="Conservative"; flux=True selects treatment of flux variables. weight_matrix_path allows creating/reusing weights, and only_create_wm=True only creates weights. keep_nan and fix_border control NaN preservation and nearest-neighbour border handling.

For vertical interpolation use source.interpolate_vertical(new_levels=[100, 500], kind="linear", extrapolate=None), with target levels in the source vertical coordinate units. The result is a new object unless overwrite=True. extrapolate=None fills outside the range with NaN; True extrapolates; False uses bottom/top values. A two-item tuple controls the two sides independently.

See interpolation tutorials.