mgr2obc v3.2.3¶

Mercurial revision 5770:c90c3015e72d | 2026-05-22

Description¶

mgr2obc builds tidal boundary condition files for a specific grid based on tide gauge harmonics (MGR files). This tool is useful for generating open boundary conditions (OBC) for numerical models, ensuring accurate tidal forcing at the boundaries of the computational domain.

Usage¶

/home/softs/tools/debug/src/mgr2obc [OPTIONS] wave1 [wave2 ...]

Options¶

Option	Description
`-h`, `--help`	Show this help and exit.
`--quadrangle`	Force the finite element (FE) grid to use quadrangles instead of triangles.
`--grid <options>`	String specifying grid options for structured grid generation.
`--append`	Append the new waves to an existing OBC file. Ensure the output file name is set using `-o`.
`-dmax <value>`	Maximum depth (in meters) to select tide gauges. Default: `4.0`.
`-m <file>`	Path to the nei file of the mesh (mesh connectivity).
`-b <file>`	Path to the bel file of the mesh (boundary elements).
`-g <file>`	Path to the MGR file(s) containing tide gauge harmonics. Can be called multiple times for multiple files.
`-o <file>`	Output file name for the OBC file. Default: `tides.obc`.
`-p <path>`	Path to the directory containing all input files.
`--debug`	Activate debug mode for verbose output.

Examples¶

Basic Usage¶

Generate an OBC file for waves M2 and S2 using default settings:

mgr2obc -m mesh.nei -b mesh.bel -g tide_gauges.mgr -o output.obc M2 S2

Using Quadrangle Elements¶

Force the grid to use quadrangles instead of triangles:

mgr2obc --quadrangle -m mesh.nei -b mesh.bel -g tide_gauges.mgr -o output.obc M2 S2

Appending to an Existing OBC File¶

Append new waves (K1, O1) to an existing OBC file:

mgr2obc --append -m mesh.nei -b mesh.bel -g tide_gauges.mgr -o existing.obc K1 O1

Custom Maximum Depth¶

Set a custom maximum depth (10.0 meters) for tide gauge selection:

mgr2obc -dmax 10.0 -m mesh.nei -b mesh.bel -g tide_gauges.mgr -o output.obc M2 S2

Specifying Grid Options¶

Use custom grid options for structured grid generation:

mgr2obc --grid "resolution=0.1,method=bilinear" -m mesh.nei -b mesh.bel -g tide_gauges.mgr -o output.obc M2 S2

Debug Mode¶

Enable debug mode for verbose output:

mgr2obc --debug -m mesh.nei -b mesh.bel -g tide_gauges.mgr -o output.obc M2 S2

Using Multiple MGR Files¶

Specify multiple MGR files for tide gauge data:

mgr2obc -m mesh.nei -b mesh.bel -g tide_gauges1.mgr -g tide_gauges2.mgr -o output.obc M2 S2

Custom Output Directory¶

Specify a custom directory for input files:

mgr2obc -p /path/to/files -m mesh.nei -b mesh.bel -g tide_gauges.mgr -o output.obc M2 S2

Environment Variables¶

mgr2obc does not rely on specific environment variables. However, ensure that:

All input files (mesh, MGR, etc.) are accessible from the specified paths.
The output directory (if custom) has write permissions.

Notes¶

Input Files:

The nei file (-m) defines the mesh connectivity.
The bel file (-b) defines the boundary elements of the mesh.
The MGR file(s) (-g) contain the harmonic constants for tide gauges.

Wave Selection:

Waves (e.g., M2, S2, K1) must be specified as arguments. These correspond to tidal constituents in the MGR files.
If a wave is not found in the MGR file, the tool will exit with an error.

Depth Filtering:

Tide gauges are selected based on their distance from the boundary points. Only gauges within the specified -dmax depth are included.

Grid Options:

The --grid option allows customization of structured grid generation. Refer to the tool’s internal documentation for supported options.

Appending Waves:

When using --append, ensure the existing OBC file is compatible with the new waves being added.

Debug Mode:

Use --debug to print detailed information about tide gauge selection and processing.