map-converter v3.2.3¶

Mercurial revision 5770:c90c3015e72d | 2026-05-22

Description¶

map-converter is a tool designed to convert the format of topographic files. Currently, it supports IGN ASCII files as input and converts them to NetCDF and GDR formats.

Usage¶

map-converter [OPTIONS] file

Options¶

Option	Description
`-h`, `--help`	Display help and exit.
`-inv`, `-inverse`	Invert the topography (multiply by `-1`).
`-scale <value>`	Apply a scaling factor to the topography (GDR format only).
`-mask <value>`	Set the mask value for the topography.
`--proj=<proj4_string>`	Convert Cartesian coordinates to spherical coordinates using the provided PROJ.4 string.
`-o <rootname>`	Set the root name for the output file(s).
`-v <name>`	Set the variable name for the output.

Deprecated Options¶

Warning: These options are deprecated and may not be supported in future versions.

Option	Description
`-b <file>`	Path to the bathymetry file.
`-p <file>`	Path to the polygon file to limit the conversion area.
`-iF <format>`	Input format (no longer required).
`-oF <format>`	Output format (no longer required).

Examples¶

Basic Conversion¶

Convert an IGN ASCII file to NetCDF:

map-converter input.xyz -o output

Invert Topography¶

Invert the topography values (multiply by -1):

map-converter input.xyz -inverse -o output

Apply Scaling Factor¶

Apply a scaling factor of 10.0 to the topography (GDR format):

map-converter input.xyz -scale 10.0 -o output

Set Mask Value¶

Set a custom mask value (e.g., 9999.0):

map-converter input.xyz -mask 9999.0 -o output

Convert Cartesian to Spherical Coordinates¶

Convert Cartesian coordinates to spherical using a PROJ.4 string:

map-converter input.xyz --proj="+proj=longlat +datum=WGS84" -o output

Set Variable Name¶

Set a custom variable name (e.g., elevation):

map-converter input.xyz -v elevation -o output

Full Conversion Example¶

Convert an IGN ASCII file to NetCDF with inverted topography, scaling, and a custom variable name:

map-converter input.xyz -inverse -scale 10.0 -v elevation --proj="+proj=longlat +datum=WGS84" -o output

Environment Variables¶

map-converter does not rely on specific environment variables. However, if you are using PROJ.4 for coordinate transformations, ensure that the PROJ_LIB environment variable is set correctly to locate PROJ.4 data files.

Notes¶

Input File Format:

Currently, only IGN ASCII files are supported as input.

Output Formats:

The tool generates NetCDF and GDR files by default.
The output file name is constructed using the root name provided with -o.

Mask Handling:

The -mask option allows you to define a value that represents missing or invalid data in the input file.

Coordinate Conversion:

Use --proj to convert Cartesian coordinates to spherical coordinates. The PROJ.4 string must be valid.

Topography Inversion:

The -inverse or -inv option is useful for converting between elevation and depth (bathymetry).

Scaling:

The -scale option is only applicable for GDR output format.