phdenzel / model-zapper

Zapp through GLASS lens models

ModelZapper

ModelZapper is a supplementary app to GLASS which can inspect, analyze, and filter GLASS “states”. Free-form gravitational lens modelling techniques which are used in GLASS, generally try to deal with the mass-sheet degeneracy (an intrinsic problem in gravitational lens modelling) by exploring the solution space in a Monte-Carlo sampling approach. Every lens model is therefore built out of many different models that solve the lens equation with the given priors. Such an ensemble model usually looks fine on average, but not all models in the ensemble might be valid or realistic solutions to the observed lens. This is where ModelZapper comes in. With this app, one can manually go through the GLASS ensemble and select realistic models, filter out the unrealistic solutions, and save the filtered ensemble in a new GLASS state.

Binaries can be directly downloaded here (currently only for macOS).

Setup

Generally, modelzapper.py should be runnable without installation. Just make sure to properly add the pre-installed glass paths to the PYTHONPATH (for an example see: setenv) before running

python modelzapper.py

Install

To properly install modelzapper.py (in order to build the app yourself or to run the app within a virtual python environment), first run configure in the root directory of the repo.

./configure

This will set up a virtual python environment and download all required libraries. After the environment and required libraries are downloaded, use install

./install

This will compile the glass source code into src, and move the build into libs and includes directories. If glass was compiled without errors, modelzapper.py should be able to run (without setting any PYTHONPATH or PATH) as

python modelzapper.py [gls.state]

Build the app

Once you configured and installed modelzapper.py, building the app is easy! Enter the virtual environment and run py2app with

source activate
python setup.py py2app

or alternatively use

./rebuild

After the command(s) finish, you should find two new directories in your repo, dist and build. In dist you’ll find your standalone macOS app that is ready to be double-clicked.

Requirements

To build the app yourself, you need a Python framework with an integrated Tkinter library (or linked to Tcl/Tk frameworks). The app relies on several python modules which are installable via e.g. pip. Since the app interfaces with glass, a runnable version of glass is essential. To summarize (also see requirements.txt):

• Python framework (==2.7)
• Tkinter (built-in or linked to Tcl and Tk frameworks (>= 8.6))
• glass
• virtualenv
• numpy
• scipy
• matplotlib
• PIL

More

Since it is not really easy to install glass, let alone automatically, chances are you might have problems running the app. If so, try building it yourself. In order to be able to build the app though, python must be installed as a framework. It is also recommended to install a newer Tcl/Tk framework than the one that comes with the macOS system. For more details see https://github.com/phdenzel/local-python-install (try installing the frameworks in standard locations though, e.g. /Library/Frameworks/).