Following the proposal and discussions at the most recent code team telecon (http://great3.pbworks.com/w/page/55276289/Code%20team%20telecon%2010%20July%202012), the fourth GalSim general milestone will be focused on completing some of the outstanding tasks that remain before we distribute the code among the GREAT3 collaboration for wider testing.

The primary items to be tackled for this milestone are:

• Implementing a system for generating spatially correlated lensing shears according to a specified power spectrum (Issue #216).

• A push to complete checking for installation / build issues on a wider range of systems and compilers, like 32-bit linux, clang compilers... (Issue #130).

• Completing the re-implementation of the config system (Issue #148), including the addition of specifying statistical distributions for object parameters, and exploring a system for describing field properties more generally (Issue #99).

We also have a couple of issues that we hope to try and address time permitting, over this summer period:

• Look at aspects of the use of real galaxy images, especially timing and streamlining I/O and data handling, along with (although much more work) tests for shear accuracy (Issue #168).

• Think about the executable script / front end for GalSim, as the config work develops.

Deadline: 4 weeks (+2 two working days) to finish on Friday 10 August 2012