Changelog-1.9

WSClean Version 1.9
Released 2015-08-21

Summary: This release introduces some major changes, both under and above the hood. First of all, there are two new deconvolution methods: IUWT deconvolution, which is similar to MORESANE, and a new multiscale algorithm that is much more accurate than the previous algorithm. The 'channelsout' multi-frequency option now treats multi-measurement-set imaging properly. Finally, all combinations of "-joinchannels", "-joinpolarizations", "-channelsout", "-pol ..", "-iuwt" and "-multiscale" that one can possibly wish are supported.

Note that WSClean now needs Casacore 2.0 or higher, with C++11 support turned on.

Full list of changes:

• New multi-scale algorithm which is more accurate, somewhat slower in most cases, but still fast. Enabled with option "-multiscale".
• The older algorithm is now available with option "-fast-multiscale", but should probably not be used for anything serious.
• The multi-scale mode now supports masks (#38).
• A new IUWT compressed sensing algorithm which is comparable to MORESANE, but allows multi-frequency deconvolution and is faster on CPU.
• Support dividing total bandpass using -channelsout when specifying multiple MSs of different frequencies. (#44)
• Rewrote the deconvolution code to use the generic ImagingTable. This allows jointly cleaning over less common polarizations combinations (e.g. Stokes I and Q) as well as cleaning channels jointly without jointly cleaning the polarizations. (#39)
• WSClean's gridding engine (class WStackingGridder) has been refactored, and it is now possible to reuse the gridder (API docs).
• Add -moresane-sl parameter to set MORESANE deconvolution depth levels per iteration (patch by O. Smirnov).
• Code was converted to Casacore 2: version 2 or higher compiled with C++11 support is now required.
• Bugfix: Add prefix to MORESANE input filenames, to avoid clashes with parallell imaging runs (#48, patch by O. Smirnov).
• Bugfix: Conversion from circular to Stokes Q, and from Stokes to circular was not implemented (/correctly). Cotton-Schwab iterations are now possible with circular feeds (e.g. JVLA). (#45)
• Bugfix: Report error when specifying invalid channel range.
• Bugfix: Removing -imaginarypart parameter from wsclean's help, as it has been replaced (way back) by combined real/imag imaging for xy/yx.
• Bugfix: Make it easier to build with platform independence (#50).
• Bugfix: WSClean could crash on zero-length selection (either because of no rows in the selection or no channels in selection).
• Bugfix: Better error message when mmap fails.
• Bugfix: Changing console output of prediction step to correspond with FTs/prediction stage, and removing redundant 'Rows that were required' output
• Lots of cleaning up and renaming.

André Offringa