Version 2.2
~~~~~~~~~~~
* Correct scaling of autocorrelations for LBA-format data
* Optimized corner turners implemented for interlaced VDIF
* Fixed a scaling bug for zoom band data
* Allow building without IPP (needs fftw) [Thanks Richard Dodson!]
* .pc files now include full compile-in info for ipp or fftw as appropriate
* Check for a common .dir file anomoly caused by hand editing
* Stop 0.5 ns delay wobble in 2 Gbps Mark5B format
* c++11 compliance
* Finally, kill off the MODE errors and Stale data errors for cases where
  subintegration time is between 1 and 2 seconds long.  This enables 1 Hz
  resolution.
* Use openmp to parallelize common corner turners for VDIF
* Fix weights (and maybe more) for setups differing only by pcal setup (Adam)
* Defeat data "echoes" that that would occur on each scan start after files
  ran out of data
* Properly scale multicast weights when selecting bands or performing zooms
* Avoid a rounding error which can lead to wrong scan choice when playing back
  nativemk5 VDIF data
* Tagged as DiFX 2.2, May 31, 2013

Version 2.1
~~~~~~~~~~~
* Version number change from 2.0.2 prior to tagging
* Tagging Version 2.1, May 4, 2012

Version 2.0.2
~~~~~~~~~~~~~
* Correctly scale cross-correlation amplitudes for pulsar binning when using Tsys>0 (accounts for varying # samples per bin c.f. nominal)
* Correctly scale LBA format visibilities, reducing the size of ACCOR corrections
* Fix bug when pulsar binning/gating and xmaclength > nfftchan
* Add collection of drive statistics to native Mark5
* guardns was incorrectly (overzealously) calculated in mpifxcorr
* "Mk5DataStream::calculateControlParams: bufferindex>=bufferbytes" bug fixed
* Low weight reads could result in uninitialized memory
* Streamstor XLRRead() bug work-around installed several places (read at position 0 before reading at position > 0)
* mpifxcorr terminates correctly for all short jobs - previously it hung for jobs with a number of subints between nCores and 4 x nCores
* multithread VDIF support enabled for nativemk5datastream (reading from a module) inclduing stripping of non-VDIF packets
* Add "FAKE" as new datastream type.  Results will be useless but benchmarking and bugfixing may benefit

Version 2.0.1, 2011 June 12
~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Added new checkmpifxcorr utility
* Updates to phase cal extraction
* Added switched power detection (enable with TCAL FREQUENCY, optional line just above PHASE CAL INT (MHZ) ), currently only for mark5access based unpackers, and only works on 2-bit data.
* Fix parsing of mark5 directory files: stepping through extra parameters had a bug.
* Native Mark5: Swap order of fill pattern setting and bank mode setting to better work around certain module problems
* Fix zoom-bands for all but special cases that just worked despite the logic in the code. (WFB paraphrasing for ATD)
* Allow number of scans on a Mark5 module to exceed 1024
* Fix calculation of bytes from guardns

Version 2.0.0, 2010 July 14
~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Many bugfixes to both band matching and multiple phase centres
* Visibilities now written out in binary format
* New polyco parser and checker is more forgiving of TEMPO2 generated polycos
* Can now produce kurtosis dumps every STA under the command of difxfilterbank
* Many nativemk5 inmprovements migrated from 1.5
* Decorrelation correction is applied if uv shifting is done
* Catch rare datastream error where file ends exactly at end of databuffer 
  for a Mk5 files
* Allow for new VEX FILE line in calc file to be optional
* Bugfix for polycos with more than one entry
* Many more minor bugfixes

Version 2.0, 2009 September 24
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Many, many changes both visibly and under the hood
* Allows support of multiple phase centres
* Writes each pulsar bin/source to a different DiFX file
* More efficient implementation of station-based processing, using
  complex multiplications to replace many sin/cos calculations (~20% speedup)
* More cache-efficient implementation of baseline-based processing
  for correlations with many channels where whole output array can't
  fit in cache simultaneously (factor of ~2 speedup for >=2k channels)
* Allows support of zoom bands
* Replaces blockspersend with subintNS, guardBlocks with guardNS
* Shifts numchannels/oversample/decimation etc from Configuration to Freq
* Allows use of Rule table in input file
* Adds support for LO offsets
* mostly complete Mark5B support
* Mark5B eVLBI support
* Visibilities with zero weight are not written to disk
* See http://cira.ivec.org/dokuwiki/doku.php/difx/documentation for more info
  on changes, particulaly for the file formats

Version 1.5 Perth, 2008 March 7
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This version was born from the merge of the main trunk code and Walter's
native-mark5 branch.  In addition some new features were added:

1. Input file

  * HEADER O/RIDE is removed (never used) and replaced with
VIS BUFFER LENGTH, which was a compile-time constant.  Typical values for
this number are upwards of 8.

  * In the configuration table, two additional parameters have been added
after NUM CHANNELS:

  CHANNELS TO AVERAGE
  OVERSAMPLE FACTOR

Currently both of these only accept value 1.

  * In the datastream table, the format and data source parameters have
changed.  The four following parameters are now used:

  DATA FORMAT
  QUANTIZATION BITS
  DATA FRAME SIZE
  DATA SOURCE

2. Difx format output

  * WEIGHTS WRITTEN replaced with DATA WEIGHT.  The value is a float ranging
from 0.0 to possibly a bit more than 1.0, but no more than 2.0; the average
weight over many seconds of data should not exceed 1.0.

  * Exactly NUM CHANNELS of data are written out.  For upper sideband data
the first written channel is the DC channel and for lower sideband data
the last written channel is the DC channel.  The Nyquist channel is always
dropped.