Source Grid Setup

How to set up the source grid for remapping.

Overview

The source grid defines the spatial representation of the data to be remapped. It can be created from various grid types, such as latitude-longitude grids, MPAS meshes, or projected grids.

Methods

• src_from_lon_lat: Create a source grid from latitude and longitude arrays.

• src_from_mpas: Create a source grid from an MPAS mesh file.

• src_from_proj: Create a source grid from a projected grid.

Example

from pyremap import Remapper

remapper = Remapper()
remapper.src_from_lon_lat(lat, lon)

Regional vs. Global Grids

By default, both src_from_lon_lat and dst_from_lon_lat determine whether a 1D lat/lon grid is regional or global automatically, based on whether the grid is periodic in longitude (i.e. its longitudes wrap a full circle). Latitude extent does not affect this: a zonally periodic but latitude-bounded grid (a polar cap or zonal band) is treated as global so that longitude wraps across the antimeridian.

The optional regional argument overrides this auto-detection. Pass regional=True to force a grid to be treated as regional or regional=False to force it to be treated as global:

remapper.src_from_lon_lat('grid_file.nc', regional=False)

Setting Source Descriptor Directly

The src_descriptor attribute can be set directly to define the source grid. This is useful when you already have a pre-defined grid descriptor or need additional capabilities not provided in the src_from_*() methods.

Example

from pyremap import Remapper, LatLonGridDescriptor

lat_lon_descriptor = LatLonGridDescriptor.read(file_name='grid_file.nc')
remapper = Remapper()
remapper.src_descriptor = lat_lon_descriptor