The following describes the most significant changes which have
occurred in the AST library between versions V3.1 and V3.2:
- A new
function astPutCardsastPutCards
has been added to the FitsChanFitsChan class. This allows multiple concatenated header
cards to be stored in a FitsChan in a single call, providing an alternative to
the existing
astPutCards function.
- Some signficant changes have been made to the simplification of Mappings
which should resultin a greater degree of simplication taking place.Some
bugs have also been fixed which could result in an infinite loop being
entered when attempting to simplify certain Mappings.
- The FitsChan class now translates the spectral algorithm codes
“-WAV”, “-FRQ” and “-VEL” (specified in early drafts of paper III) to
the corresponding “-X2P” form when reading a spectral axis description
from a set of FITS header cards.
- A bug has been fixed in the FitsChan class which could cause
keywords associated with alternate axis descriptions to be mis-interpreted.
- The PlotPlot class now provides facilities for modifying the appearance
of sub-strings within text strings such as axis labels, titles, etc,
by producing super-scripts, sub-scripts, changing the font colour, size,
etc. See attribute EscapeEscape.
- The default value of the TolTol attribute of the Plot class has been
changed from 0.001 to 0.01. This should not usually cause any significant
visible change to the plot, but should make the plotting faster. You may
need to set a lower value for Tol if you are producing a particularly
large plot.
- The algorithm for finding the default value for the Gap attribute
has been changed. This attribute specifies the gap between major axis
values in an annotated grid drawn by the Plot class. The change in
algorithm may cause the default value to be different to previous versions
in cirtain circumstances.
- Some bugs have been fixed in the Plot class which could cause the
system to hang for a long time while drawing certain all-sky grids
(notable some of the FITS Quad-cube projections).
- The SkyAxisSkyAxis class has extended the Format attribute by the addition
of the “g” option. this option is similar to the older “l” option in that
it results in characters (“h”, “m”, “s”, etc) being used as
delimiters between the sexagesimal fields of the celestial position. The
difference is that the “g” option includes graphics escape sequences
in the returned formatted string which result in the field delimiter
characters being drawn as super-scripts when plotted as numerical axis values
by a Plot.
- The Plot class has been extended to include facilities for producing
logarithmic axes. See attributes LogPlot, LogTicks, LogGap and LogLabel.
- New functions astGCap and astGScales have been added to the interface
defined by file
grf.h
. The ast_linkast_link command has been modified so
that the -mygrf
switch loads dummy versions of the new grf
functions. This means that applications should continue to build without
any change. However, the facilities for interpreting escape sequences
within strings drawn by the Plot class will not be available unless the
new grf functions are implemented. If you choose to implement them, you
should modify your linking procedure to use the -grf
switch in
place of the older -mygrf
switch. See the description of the ast_link
command for details of the new switches. Also note that the astGQch
function, whilst included in verb+grf.h+ in pervious versions of AST, was
not actually called. As of this version of AST, calls are made to the
astGQch function, and so any bugs in the implementation of astGQch may
cause spurious behaviour when plotting text strings.
- A new 'static' method called astEscapesastEscapes has been added which is used
to control and enquire whether astGetC and astFormatastFormat will strip any graphical
escape sequences which may be present out of the returned value.
- New attribute XmlPrefixXmlPrefix has been added to the XmlChanXmlChan class. It
allows XML written by the XmlChan class to include an explicit namespace
prefix on each element.
- New attribute XmlFormatXmlFormat has been added to the XmlChan class. It
specifies the format in which AST objects should be written.
- A new class of MappingMapping, the TranMapTranMap, has been introduced. A TranMap
takes its forward transformation from an existing Mapping, and its inverse
transformation from another existing Mapping.
- A bug has been fixed in WcsMapWcsMap which caused error reports to
include erroneous axis numbers when referring to missing parameter values.