Installation

To install roman_photoz, simply use pip:

pip install roman_photoz

Development

To install the development version of roman_photoz, you can clone the repository and install it in editable mode:

Clone the repository:

git clone https://github.com/spacetelescope/roman_photoz.git

Navigate to the project directory:
```
cd roman_photoz
```
Install package in editable mode. For example, on macOS:
```
pip install -e ".[dev]"
```

Bootstrap data/model setup

Run roman-photoz --setup to download the LePhare auxiliary data required by the Roman config, create a simulated catalog and Roman filter files, build the model (informer stage), trim LEPHAREDIR to the files needed by the estimator, and verify that the required artifacts are present:

Set the environment variables (recommended). roman-photoz uses LEPHAREDIR and LEPHAREWORK to determine where to store the LePhare data and work directories:
```
export LEPHAREDIR=/path/to/lephare_data
export LEPHAREWORK=/path/to/lephare_work
```
If you don’t set them, lephare falls back to its own default cache directories (typically under ~/Library/Caches/lephare on macOS, or the platform equivalent elsewhere) and prints a notice showing the full paths it chose. Setting the variables yourself gives you control over where these (potentially large) files are stored.

roman-photoz also looks for an INFORMER_MODEL_PATH environment variable to determine where the informer model file (roman_model.pkl by default) is read from/written to. It may point either at the model directory or directly at the pickle file. It defaults to LEPHAREWORK if not set, so you only need to set it explicitly if you want to read/store the model somewhere else:
```
export INFORMER_MODEL_PATH=/path/to/model_dir
# or:
# export INFORMER_MODEL_PATH=/path/to/model_dir/roman_model.pkl
```
Run:
```
roman-photoz --setup
```
Options:
- --nobj N – number of objects in the simulated catalog (default: 1000).
- --simulated-catalog-filename FILE – simulated catalog filename (default: roman_photoz_simulated_catalog.parquet).
This leaves a catalog behind at $LEPHAREWORK/roman_photoz_simulated_catalog.parquet (it already has redshift estimates added by setup’s own model-building pass). This catalog isn’t meant to be your real input data – it’s a fallback you can use in step 3 below if you don’t have your own catalog yet (see “Creating a fresh simulated catalog” below for another option).

Setup also creates a sibling informer run directory at dirname($LEPHAREWORK)/inform_roman. That tree contains the SED libraries used by estimation (for example lib_mag/QSO_COSMOS.doc) and must be packaged together with lephare_data and lephare_work when the assets are copied to another host.

Note

roman-photoz --setup only needs to be run once per LEPHAREDIR/LEPHAREWORK location – it downloads the auxiliary data and builds the informer model, which are then reused for all subsequent roman-photoz runs. There’s no need to run it again unless you delete/change those directories.
Note

Relocatable packaging expects this layout (names can vary, sibling relationship matters):
```
package_root/
  lephare_data/     # LEPHAREDIR
  lephare_work/     # LEPHAREWORK, includes roman_model.pkl
  inform_roman/     # informer run dir used by estimation
```
roman-photoz rewrites absolute host paths from roman_model.pkl at runtime and forces estimation to use the local inform_roman directory derived from LEPHAREWORK. Still copy all three trees together; lephare_work alone is not sufficient.
Run roman-photoz. Assuming there is a folder named OUTPUT in the current working directory where the updated catalog containing the redshift results will be saved to:
```
roman-photoz \
  --input-filename <path/to/your_catalog.parquet> \
  --output-filename ./OUTPUT/<path/to/your_catalog.parquet>
```
--input-filename should point to your own input catalog. If you don’t have one, you can pass in the catalog created in step 2 instead: $LEPHAREWORK/roman_photoz_simulated_catalog.parquet.

Creating a fresh simulated catalog (optional)

If you’d rather not reuse the catalog from step 2 – for example, you want a different number of objects or different physical parameters – generate a fresh one:
```
roman-photoz-create-simulated-catalog \
  --output-filename roman_photoz_simulated_catalog.parquet \
  --refresh-lib-mag
```
To change the physical parameters used to generate the simulated catalog (e.g. redshift range/step), edit roman_photoz/default_config_file.py.