https://github.com/lsst/sims_catUtils Code to add SNIa to LSST galaxy catalogs: =========================================

• sniacatalogs/snObject.py : SNObject provides a wrapping of sncosmo.model adding a few attributes, and methods to use catsim framework to obtain fluxes and magnitudes after extinction.
• sniacatalogs/snUniverse.py : Contains rules of distribution of SN model parameters.
• sniacatalogs/sncat.py : Instance catalog of SN instantiated using the SNObject class in snObject.py drawing galaxy information from a galaxy catalog.

• Requires basic SNCosmo (https://github.com/sncosmo/sncosmo) sncosmo v1.0.x can be installed via pip. This is also present in the LSST simulation stack. The instructions for SNCosmo installation are provided in http://sncosmo.readthedocs.org/en/latest/install.html. I typically have a fork of the SNcosmo distribution and on the top level SNCosmo directory use:

  >>> python setup.py build

  and add the path to the created library in build to

  ${HOME}/.local/lib/python2.7/site-packages/mypaths.pth

• LSST Simulation Stack: You will need to install a release of the LSST simulation stack. Further, you will need to use the following development versions of packages in the LSST simulation stack using the master branch.

  • sims_catalogs_generation
  • sims_photutils
  • sims_catalogs_measures
  • sims_utils
  • sims_catutils
  • sims_coordutils
  • sims_data
  • sims_maf
  • sims_catalogs_generation
  • sims_catalogs_measures

  The instructions for installing a release of a lsst simulation stack and setting up development versions so that you can use the development versions when evailable and fallback on the release when no development version is on your computer are in https://confluence.lsstcorp.org/display/SIM/Catalogs+and+MAF.

  • I am also assuming that you have a anaconda python installed. Some example ipython notebooks can require sqlite3, pandas, seaborn (the last one can be commented out)

• Setup sniacatalogs: Clone the package on your computer, and from SNIaCatalogs directory:

  >>> python setup.py install --user

After setup, go to the examples directory under the package. Fire up ipython notebook at this location and open the file - SNinCatSim.ipynb and evaluate the cells. The notebook should look like http://nbviewer.ipython.org/gist/anonymous/deb1821e8f69def6d7b5 if everything works as expected. - This requires sqlite3, pandas, seaborn which are all part of anaconda. If Without seaborn, everything will run, so if you do not have seaborn just comment out the lines.

These are really part of updates to SNCosmo simulation capabilities

1. Add uncertainties (at some approximation, easy, harder with images)
2. Add intrinsic scatter (will take time)
3. Tune Distributions of SN model parameters

older: (outdated) -----src/snIa.py is an instance catalog class to interact with the lsst database src/snIacLass_t.py is an independent class which interacts with the lsst database