data_formats

4GP Data Formats

4GP stores spectra in collections called "spectrum libraries". Each library contains a database of metadata associated with each spectrum, which might include the name of the star, some stellar parameters, and abundances. This data is stored in an SQL database. Separately, the spectral data itself is stored in a numpy binary dump file.

By default, spectrum libraries are stored in a directory called workspace, which normally sits in your working copy of 4most-4gp-scripts. Each library is stored in a separate subdirectory within workspace.

The metadata is stored in an SQLite3 database file alongside the binary files, so libraries may be transferred from one machine to another simply by copying the relevant subdirectory from the workspace directory.

Beyond this, you should never tamper with the contents of these directories except via the fourgp_speclib module. Don't imagine that you can copy or delete the binary numpy files to move spectra between libraries, because the metadata database needs to be kept up to date too. There are python scripts in the 4most-4gp-scripts for doing these kinds of manipulations properly. This includes, for example, python scripts to import and export spectra to/from other formats into a 4GP library.