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Getting started

Installation

pip install .            # from the repository root
# or, for development:
pip install -e .

Minimal required packages (installed automatically): fitsio, numpy, scipy, matplotlib, picca.

Optional:

  • pyevtk — to export a tomographic box to VTK for 3D visualisation.
  • SaclayMocks — used by lelantos.boxdm; a vendored fallback copy ships under lelantos/saclaymocks/, but installing SaclayMocks directly is recommended.

The tomographic solver

To run the reconstruction you must place the executable of the tomographic algorithm in lelantos/lelantos/exec/. The only algorithm currently supported is Dachshund (a Wiener-filter reconstruction), expected as dachshund.exe.

Two ways to run

1. The all-in-one interface

Copy and edit scripts/interface_example.ini (a fully commented reference is provided as scripts/interface_explanatory.ini), then run:

lelantos_interface.py interface_example.ini

Each stage is switched on/off by a boolean in the [main] section. See the Pipeline & config page for the meaning of every option.

2. Individual launchers

The launchers/ folder holds standalone scripts that expose one stage each. Edit the variables at the top of the file and run it directly, e.g.:

python launchers/lelantos_convert_delta.py
python launchers/lelantos_void_finder.py

The scripts/ folder additionally provides small argparse / config-parser utilities to inspect or modify tomographic objects (print a property file, cut a QSO/DLA catalog, show void statistics, …).

Coordinate & unit conventions

  • RA / Dec are handled in radians internally (degrees at the plotting boundary), comoving distances and box sizes in Mpc·h⁻¹, velocities in km/s and wavenumbers in h/Mpc.
  • The sky ↔ cartesian transform is selected per run by coordinate_transform (middle, full_angle/full, or cartesian). Most downstream code assumes the middle tangent-plane transform.
  • The fiducial cosmology enters only at the delta-conversion step, through Omega_m.