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CALCOS v2.19.6 Release Notes

---------------- CALCOS v2.19.6 ----------------------------------
This describes changes from calcos version 2.18.5 to 2.19.6 (version
2.19.7 is the same as 2.19.6 except for the installation procedure).

Relevant Trac tickets and PRs:
Trac   PR
----  -----
 616  66158  Calcos should be modified to use Sphinx for documentation.
 720  68550  Calcos should accept data taken with different cenwaves.
 918  71634  G140L Segment B only: no SHIFT applied
 919  71762  Calcos should read the TIME column as double.
 924  71881  Calcos should use the HAS_LINES column in the LAMPTAB.
 925  71949  Calcos should use the FPOFFSET column in the DISPTAB.
 927  71997  Calcos should create the output directory.
 928  71998  Calcos should use the Gehrels variance function.
 930  72008  Calcos should use fp_pixel_shift for wavecals.
 936  72063  Calcos should ignore difference in SPWCSTAB for a wavecal.
 938  72065  Calcos should include error estimate in the weight.
 939  72066  Change the sign of calcos variables mindopp and maxdopp.
 940  72067  Calcos should broaden flagged regions in the DQ array.
 943  72166  Change the tests in calcos for an empty table.
 946  72494  Calcos should copy association file to output directory.
 960  72794  Calcos should do the Doppler correction after csum.
 963  72824  Bug in calcos normalization for average wavecal shifts.

If the user specified an output directory but that directory doesn't
exist, calcos will create it.

If the input is an association file and an output directory was specified,
the input association file will be copied to the output directory, and the
copy (rather than the original) will be updated.  This allows running
calcos on write-protected data.

If the lamptab has a HAS_LINES column, the value in this column will be
used to determine whether to copy wavecal information from segment A
to segment B data.  This was previously done only for G140L data.

If the disptab has an FPOFFSET column, this will be used (in addition to
other keywords) to select the appropriate row of the disptab.

The Gehrels variance function is now used to compute the error estimates
for the flt and counts files and for the ERROR column in the x1d and
x1dsum tables.

When averaging x1d spectra to an x1dsum, the flat field is included in
the weight.  The primary reason for this is to give less weight within
the grid wire shadows.

When flagging regions as bad in the DQ extension, the regions will be
expanded by a quarter of a pixel in each direction.  This reduces the
number of cases where a pixel should have been flagged as bad but wasn't
due to roundoff to integer pixel number.

In the case that there is a non-tagflash exposure with no auto/GO wavecal
at the same fpoffset, another wavecal in the association can be used, and
the correction due to different fpoffset will be taken from the
FP_PIXEL_SHIFT column in the lamptab.

The Doppler correction and filtering by pulse height are now done after
the call to write the csum file, and checking for FUV bursts is now done
after wavecal correction.  The Doppler correction uses the dispersion and
1-D extraction reference tables (DISPTAB and XTRACTAB), and there may
be situations where these tables do not contain rows for some mode,
but it is desired to do some calibration (e.g. GEOCORR) and write a csum
file before stopping with an exception.  It was possible to move Doppler
correction because the csum file does not depend on it; however, the
primary header keyword DOPPCORR will now be 'PERFORM' instead of
'COMPLETE' in csum files.  Checking for bursts makes use of the Y
locations of the source and background regions, and these will not be
known until after wavecal correction, so moving the burst correction
should improve the results, i.e. version 2.19.6 should be less likely
to find bursts unless they are real.