ras-commander-fast-hdf

The default HDF engine of ras-commander: a native (Rust) reader for HEC-RAS HDF files.

ras-commander's Hdf* classes read plan results, geometry, terrain and land-cover HDF files through this engine. Results are identical to the h5py reference implementation (values, dtypes, columns, index, CRS, attributes and exceptions). Large reads are faster: 2D cell polygons 4–19× depending on mesh size, and mesh time series 2–8× on large meshes. Small reads are up to a few milliseconds slower. In the default auto mode, any read the engine refuses uses h5py.

Install

ras-commander installs this package automatically on Windows x64, Linux x64 and macOS arm64 (ras-commander 0.108.0 and later install 0.2.x; 0.107.1 installs 0.1.x), so this is enough:

pip install ras-commander

With ras-commander 0.107.0, install both: pip install ras-commander ras-commander-fast-hdf.

from ras_commander import fast_hdf
fast_hdf.available()   # True

Wheels: Windows x64, Linux x64 (manylinux2014, glibc 2.17 or later; and musllinux_1_2 for Alpine) and macOS arm64, CPython 3.10 or later. No HDF5 C library or Rust toolchain is needed to install. Windows and Linux are qualified against HEC-RAS result files; macOS builds and passes the smoke tests but has not been qualified. On other platforms ras-commander does not install the engine and uses h5py for every read; the source distribution builds the engine there but needs Rust.

Engine modes

Choose the mode with RAS_COMMANDER_FAST_HDF (h5py turns the native engine off):

Links

• User guide: https://rascommander.info/ras/native-engine/
• Source, developer docs and issues: https://github.com/gpt-cmdr/ras-commander-fast-hdf
• Changelog: https://github.com/gpt-cmdr/ras-commander-fast-hdf/blob/main/CHANGELOG.md

License

MIT license. The wheel includes the licenses of every bundled crate in THIRD-PARTY-NOTICES.md.

ras-commander-fast-hdf is an independent open source project. HEC-RAS is developed by the U.S. Army Corps of Engineers Hydrologic Engineering Center (HEC). This project is not affiliated with, endorsed by, or supported by HEC or USACE.