The following describes the most significant changes that
occurred in the AST library between versions V4.4 and V4.5:
- All FITS-CLASS headers are now created with a frequency axis. If the
FrameSetFrameSet supplied to
astWriteastWrite
contains a velocity axis (or any other form
of spectral axis) it will be converted to an equivalent frequency axis
before being used to create the FITS-CLASS header.
- The value stored in the FITS-CLASS keyword “VELO-LSR” has been changed
from the velocity of the source to the velocity of the reference channel.
- Addition of a new method call
astPurgeWCSastPurgeWCS
to the FitsChanFitsChan
class. This method removes all WCS-related header cards from a FitsChan.
- The PlotPlot class has a new attribute called GrfContext that can be used
to comminicate context information between an application and any
graphics functions registered with the Plot class via the
astGrfSetastGrfSet function.
- Functions registered with the Plot class using
astGrfSet
now take a new additional integer parameter, “grfcon”. The Plot class
sets this parameter to the value of the Plot's GrfContext attribute before
calling the graphics function. NOTE, THIS CHANGE WILL REQUIRE EXISTING
CODE THAT USES
astGrfSet
TO BE MODIFIED TO INCLUDE THE NEW PARAMETER.
- The
astRebinSeq functions
now have an extra parameter that is used to record the total number of input
data values added into the output array. This is necessary to correct a
flaw in the calculation of output variances based on the spread of input
values. NOTE, THIS CHANGE WILL REQUIRE EXISTING CODE TO BE MODIFIED TO
INCLUDE THE NEW PARAMETER (CALLED "NUSED").
- Support has been added for the FITS-WCS “HPX” (HEALPix) projection.
- A new flag “AST__VARWGT” can be supplied to
astRebinSeq.
This causes the input data values to be weighted using the reciprocals of
the input variances (if supplied).
- The FrameFrame class has a new read-only attribute called NormUnit that
returns the normalised value of the Unit attribute for an axis. Here,
“normalisation” means cancelling redundant units, etc. So for instance, a
Unit value of “s*(m/s)” would result in a NormUnit value of “m”.
- A new
function astShowMeshastShowMesh
has been added to the RegionRegion class. It displays a mesh of points covering
the surface of a Region by writing out a table of axis values to standard
output.
- The Plot class now honours the value of the LabelUp attribute even if
numerical labels are placed around the edge of the Plot. Previously
LabelUp was only used if the labels were drawn within the interior of
the plot. The LabelUp attribute controls whether numerical labels are
drawn horizontally or parallel to the axis they describe.
- A bug has been fixed that could segmentation violations when setting
attribute values.