Skip to content

BH-Molecule CLI Commands

The BH-Molecule package provides three main command-line tools for generating, exporting, and plotting model spectra of the boron hydride (BH) A–X band.

Installation

To use the commands, you need to install the package. See the Installation section.

  • bh-spectra
  • bh-spectra-csv
  • bh-spectra-plot

Common Parameters

All three commands share a set of parameters controlling the generated spectrum:

Parameter Type Default Description
--xmin float 432.8 Minimum wavelength in nm
--xmax float 434.2 Maximum wavelength in nm
--points int 4000 Number of wavelength points
--C float 1.0 Concentration factor
--T_rot float 2000.0 Rotational temperature in K
--dx float 0.0 Wavelength shift in nm
--w_inst float 0.02 Instrumental FWHM in nm
--base float 0.0 Baseline offset
--I_R7 float 0.5 Intensity of R₇ branch line
--I_R8 float 0.3 Intensity of R₈ branch line

Generate Spectrum Data

bh-spectra

Generates model spectrum and saves it as a compressed NumPy file (.npz).

bh-spectra --C 5.0 --T_rot 3500 --out spectrum.npz

Options:

  • --out: Output file name (default: spectrum.npz)

Example:

bh-spectra --xmin 433.0 --xmax 434.0 --points 2000 --C 2.0 --T_rot 2500 --out my_spectrum.npz

bh-spectra-csv

Same as bh-spectra but outputs a CSV file instead of NumPy.

bh-spectra-csv --C 5.0 --T_rot 3500 --out spectrum.csv

Options:

  • --out: Output CSV filename (default: spectrum.csv)

The resulting CSV will have columns:

  • x — Wavelength (nm)
  • y — Intensity (a.u.)

Plot Spectrum

Generates and displays a spectrum plot using Matplotlib.

bh-spectra-plot --C 5.0 --T_rot 3500

Additional options:

  • --save: Save plot to file (e.g. plot.png)
  • --dpi: Resolution when saving (default: 100)
  • --figsize: Width and height in inches (default: 10 6)

Example Workflow

  1. Generate spectrum data 

    bh-spectra --C 4.0 --T_rot 3200 --out data.npz

  2. Export same parameters to CSV 

    bh-spectra-csv --C 4.0 --T_rot 3200 --out data.csv

  3. Visualize spectrum 

    bh-spectra-plot --C 4.0 --T_rot 3200 --save plot.png --dpi 200

Notes

  • The BH-Spectra CLI tools are based on the BHModel class and use molecular constants loaded via load_v00_wavelengths().
  • Adjusting C, T_rot, and w_inst has the most visible effect on spectrum shape.