GRALE is a library to model gravitational lenses and invert gravitational lens systems based on the observed images. It is written in C++ and is primarily intended to be used on a unix-like system (Linux, OS X, ...) but should work (in a limited way) on MS-Windows systems as well. The CMake build system is used to create the library. Also available is the program GRALESHELL, which is an interactive environment that provides easy access to many procedures of the GRALE library.


The following articles involve the use of GRALE:

  1. Evidence for the line of sight structure in the largest Hubble Frontier Field cluster, MACSJ0717.5+3745
  2. Model-independent and model-based local lensing properties of CL0024+1654 from multiply-imaged galaxies
  3. Dark matter dynamics in Abell 3827: new data consistent with standard Cold Dark Matter
  4. The Frontier Fields Lens Modeling Comparison Project
  5. Lens Models Under the Microscope: Comparison of Hubble Frontier Field Cluster Magnification Maps
  6. Testing light-traces-mass in Hubble Frontier Fields Cluster MACS-J0416.1-2403
  7. Quantifying substructures in Hubble Frontier Field clusters: comparison with Lambda-CDM simulations
  8. The behaviour of dark matter associated with four bright cluster galaxies in the 10 kpc core of Abell 3827
  9. Lensing time delays as a substructure constraint: a case study with the cluster SDSS J1004+4112
  10. Mass-Galaxy offsets in Abell 3827, 2218 and 1689: intrinsic properties or line-of-sight substructures?
  11. Lensing degeneracies and mass substructure
  12. Strong-Lensing Analysis of MS 1358.4+6245: New Multiple Images and Implications for the Well-Resolved z=4.92 Galaxy
  13. Full Lensing Analysis of Abell 1703: Comparison of Independent Lens-Modelling Techniques
  14. Non-parametric strong lens inversion of SDSS J1004+4112
  15. The search for dark matter via strong lens inversions of galaxy clusters using genetic algorithms
  16. Non-parametric strong lens inversion of Cl 0024+1654: illustrating the monopole degeneracy
  17. A generalisation of the mass-sheet degeneracy producing ring-like artefacts in the lens mass distribution
  18. Non-parametric inversion of gravitational lensing systems with few images using a multi-objective genetic algorithm
  19. A genetic algorithm for the non-parametric inversion of strong lensing systems


The new version consists of a set of core libraries in C++, together with Python bindings to make the use more flexible. The code for GRALE2/pygrale can be found at GitHub, the documentation can be found here.

The original software is of course also still available. The file formats used should be compatible between the versions, which is very useful as not all software (e.g.the Grale editor) has not been ported to the new version yet.