mesh2mesh v3.2.3¶

Mercurial revision 5786:5c8b45563631 | 2026-08-04

Description¶

mesh2mesh performs nearest-neighbor interpolation of simulation outputs onto another finite element (FE) grid. It is designed to remap data from one mesh to another, preserving the structure and values of the original simulation.

Usage¶

mesh2mesh [OPTIONS] file

Options¶

Option	Description
`-h`, `--help`	Display this help message and exit.
`-i <file>`	Input mesh grid file. Required.
`-o <file>`	Output mesh grid file. Required.
`-s <value>`	Value of the mask to apply (default: `999.9`).

Note: The -f option (format of the simulation file) is deprecated. The format is now automatically inferred from the file suffix (e.g., .s2r, .s2c, .v2r, .v2c).

Examples¶

Basic Interpolation for Scalar Data (S2R Format)¶

Interpolate scalar data from input.s2r to a new mesh:

mesh2mesh -i input_mesh.nc -o output_mesh.nc -s 999.9 input.s2r

Interpolate Vector Data (V2R Format)¶

Interpolate vector data (e.g., velocity components) from input.v2r:

mesh2mesh -i input_mesh.nc -o output_mesh.nc input.v2r

Interpolate Complex Scalar Data (S2C Format)¶

Interpolate complex scalar data (e.g., harmonic constants for tidal elevation):

mesh2mesh -i input_mesh.nc -o output_mesh.nc input.s2c

Interpolate Complex Vector Data (V2C Format)¶

Interpolate complex vector data (e.g., harmonic constants for tidal currents):

mesh2mesh -i input_mesh.nc -o output_mesh.nc input.v2c

Custom Mask Value¶

Use a custom mask value (e.g., -999.0) for invalid or missing data:

mesh2mesh -i input_mesh.nc -o output_mesh.nc -s -999.0 input.s2r

Environment Variables¶

mesh2mesh does not rely on specific environment variables. However, ensure that:

Input and output mesh files are accessible and in the correct format.
The simulation file suffix (e.g., .s2r, .v2c) matches the expected data type.

Notes¶

Input File Formats:

The tool automatically detects the format of the simulation file based on its suffix:
- .s2r: Scalar real data (e.g., sea surface height).
- .s2c: Scalar complex data (e.g., harmonic constants for elevation).
- .v2r: Vector real data (e.g., velocity components).
- .v2c: Vector complex data (e.g., harmonic constants for currents).

Mask Handling:

The -s option sets the value used for masked or invalid data in the output. Default is 999.9.
If a point in the output mesh does not correspond to any valid point in the input mesh, it is assigned the mask value.

Interpolation Method:

Uses nearest-neighbor interpolation for simplicity and efficiency.
For points that fall within an element of the input mesh, linear interpolation (LGP1) is applied.

Output Files:

Output files are saved with a .new.<suffix> extension (e.g., input.new.s2r).
Metadata (comments) are preserved in the output file, including the original filename and a copyright notice.

Error Handling:

The tool exits with an error if:
- Input or output mesh files are not specified.
- The simulation file format is not recognized.
- Interpolation fails for any reason.