TOPCAT v4.3-2 release

[Mark Taylor]

Hi topcat-users,

This is to announce the following releases:

    TOPCAT v4.3-2
    STILTS v3.0-6
    STIL v3.1

Points of interest described below: one bug fix, more facilities
for density plots, and changes to colour map.

Bug fix:
   This release fixes a long-standing bug in the crossmatching which
   relates to range restriction during pre-processing.
   This is not a big effect, but it could have caused some errors
   in crossmatching in previous releases (sorry!), so I describe
   the details here.
   It could have caused missed associations (but not false positives)
   near the edge of coverage regions if using per-row errors, and if
   the scale of the errors differed (especially differed significantly)
   between the matched tables.  It affected the following match algorithms
   only:

       TOPCAT match Algorithm           STILTS matcher
       ----------------------           --------------
       Sky with Errors,                 skyerr
       <n>-d Cartesian with Errors      <n>-d_err
       2-d Cartesian Ellipses           2d_ellipse
       Sky Ellipses                     skyellipse

   Thanks to Grant Kennedy (IoA) for reporting this bug.
   Note that bug reports in the crossmatching code are rare;
   see http://www.star.bristol.ac.uk/~mbt/topcat/faq.html#xmatchIssues
   for historical details.

Weighted Density plots:
   There are three new ways to do density plots; these all give you
   the new capability of weighting by an additional coordinate,
   choosing the combination method (mean, median, sum, max, ...),
   and displaying the quantitative value-colour mapping on the shared
   colour ramp (previously aux axis) beside the plot.  It's a bit like the
   existing Density shading mode, but you can use a weighting value and
   see the colour mapping on a ramp.  And it's a bit like the existing
   Aux shading mode, but it works much better for crowded plots. The
   new features are Weighted shading mode (all plots), HEALPix SkyDensity
   form (sky plot) and Density form (plane plot).

Colour map changes:
   Several new colour maps are added, including the new MatPlotLib 1.5
   ones and some diverging options. The new default colour map for
   Aux mode is no longer Rainbow! It's Inferno from MatPlotLib.

Downloads and more details of the changes are available at the usual places:

   http://www.starlink.ac.uk/topcat/
   http://www.starlink.ac.uk/stilts/
   http://www.starlink.ac.uk/stil/

thanks for reading!

Mark

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/