GalSim version 1.6.0 released.

[Mike Jarvis]

We are pleased to announce the release of GalSim version 1.6.0.  You can obtain the new version from our release page.

Most of the new features are related to the atmospheric PSFs, most notably improving the speed and accuracy of drawing these with photon shooting.  There are also some significant improvements to the Silicon sensor module.  (See below for a more comprehensive listing of the changes.) These updates will be critical for the forthcoming LSST DESC DC2 simulations, and we are very happy to be involved in that effort.

This will very likely be the final release in the 1.x series (aside from bugfix releases).  We will soon be releasing GalSim version 2.0, which will be essentially feature-equivalent, but with a new boost-free installation, which many people have been asking for.  That release will include removal of all currently deprecated features, so if your code is emitting any deprecation warnings, you would be advised to correct them soon, so you can eventually switch to the 2.x series.

As always, thank you for your interest in GalSim!  And if you have any issues or feature requests, don't hesitate to let us know.

Peace,

Mike, Rachel and Josh

On behalf of the entire GalSim development team

Changes in version 1.6:

API Changes:

• Delayed AtmosphericScreen instantiation until its first use, the nature of which can change the value of the generated screens.  Use the .instantiate() method to manually override auto-instantiation. (#864)
• Reduced the number of types for the return value of various NFWHalo and PowerSpectrum methods.  Now they either return a single value if the input `pos` is a single Position or a numpy array if multiple positions were provided. (#855)
• Changed the return values of LookupTable, SED and Bandpass, when used as a function, to only return only either a float or a numpy array. (#955)

Bug Fixes:

• Fixed error in amplitude of phase screens created by AtmosphericScreen (#864)
• Fixed a bug in the DES MEDS writer setting the cutout row/col wrong. (#928)
• Fixed a number of small bugs in the config processing uncovered by the galsim_extra FocalPlane output type. (#928)
• Fixed python3 unicode/str mismatches in tests/SConscript (#932)
• Fixed memory leak when drawing PhaseScreenPSFs using photon-shooting (#942)
• Fixed a few minor bugs in the Silicon code. (#963)
• Fixed a bug in SED.thin(), where it would always use the default rel_err, rather than the provided value. (#963)

Deprecated Features:

• Deprecated passing Image arguments to kappaKaiserSquires function. (#855)
• Deprecated the interpolant argument for PowerSpectrum methods getShear, getConvergence, getMagnification, and getLensing.  The interpolant should be set when calling buildGrid. (#855)
• Deprecated PowerSpectrum.subsampleGrid. (#855)

New Features:

• Added Zernike submodule. (#832, #951)
• Updated PhaseScreen wavefront and wavefront_gradient methods to accept `None` as a valid time argument, which means to use the internally stored time in the screen(s). (#864)
• Added SecondKick profile GSObject. (#864)
• Updated PhaseScreenPSFs to automatically include SecondKick objects when being drawn with geometric photon shooting. (#864)
• Added option to use circular weight function in HSM adaptive moments code. (#917)
• Added VonKarman profile GSObject. (#940)
• Added PhotonDCR surface op to apply DCR for photon shooting. (#955)
• Allow astropy units as wave_type in Bandpass. (#955)
• Added ability to get net pixel areas from the Silicon code for a given flux image. (#963)
• Added ability to transpose the meaning of (x,y) in the Silicon class. (#963)