The following describes the most significant changes which have
occurred in the AST library between versions V3.3 and V3.4:
- The MappingMapping class has a new method
(astLinearApproxastLinearApprox)
which calculates the co-efficients of a linear approximation to a Mapping.
- The Format attribute for simple Frames and SkyFrames has been extended.
It has always been possible, in both classes, to specify a precision by
including a dot in the Format value followed by an integer (e.g.
“
dms.1
” for a SkyFrameSkyFrame, or “%.10g
” for a simple FrameFrame).
The precision can now also be specified using an asterisk in place of the
integer (e.g. “dms.*
” or “%.*g
”). This causes the
precision to be derived on the basis of the Digits attribute value.
- The PlotPlot class has been changed so that the default value used for the
Digits attribute is chosen to be the smallest value which results in no
pair of adjacent labels being identical. For instance, if an annotated
grid is being drawn describing a SkyFrame, and the Format(1) value is set
to “
hms.*g
” (the “g” causes field delimiters to be drawn as
superscripts), and the Digits(1) value is unset, then the seconds field
will have a number of decimal places which results in no pair of labels
being identical.
- Addition of a new class classed DSBSpecFrameDSBSpecFrame. This is a
sub-class of SpecFrameSpecFrame which can be used to describe spectral axes
associated with dual sideband spectral data.
- The FitsChanFitsChan class will now read headers which use the old “-GLS”
projection code, converting them to the corresponding modern “-SFL” code,
provided that the celestial axes are not rotated.
- The FitsChan class has a new EncodingEncoding, “FITS-CLASS”, which allows
the reading and writing of FITS headers using the conventions of the CLASS
package - see
http://www.iram.fr/IRAMFR/GILDAS/doc/html/class-html/class.html).