## Changes Introduced in V8.6.2

The following describes the most significant changes which occurred in the AST library between versions V8.5.1 and V8.6.2:

1. The astRebinSeq<X> functions accepts a new flag, AST__PARWGT, which allows the initial weight to be given for the data being pasted into the output arrays (the initial weight to use should be include in the "params" array). This initial weight defaults to 1.0 if the AST__PARWGT flag is not given.

2. The behaviour of the astLinearApproxastLinearApprox method of the MappingMapping class has been changed in cases where the Mapping being approximated generates bad (AST__BAD) values for one or more of its outputs. Previously, any such Mapping would be deemed non-linear and no fit would be returned. Now, a fit is returned, provided the other outputs of the Mapping are linear, but the fit contains AST__BAD values for the coefficients describing the bad Mapping output.

3. The astWriteastWrite method of the FitsChanFitsChan class can now create FITS-WCS headers that include keyords describing focal plane distortion using the conventions of the Spitzer SIP scheme. This is however only possible if the SipOKSipOK attribute of the FitsChan is set to a non-zero value (which is the default), and the FrameSetFrameSet being written out contains an appropriate PolyMapPolyMap that conforms to the requirements of the SIP convention.

4. A new function call astCreatedAtastCreatedAt is now available that returns the function name, file path and line number at which an AST object was first created. Note, there is no Fortran equivalent to this new C function.

5. The number of digits used to format floating point values has been increased in order to avoid loss of precision when converting from binary to string and back to binary. This could cause very small changes in numerical values returned by AST functions.

6. If a FrameSet is supplied as the “map” argument to astAddFrameastAddFrame, it now extracts and stores the base->current Mapping from the supplied FrameSet. Previously, the entire FrameSet was stored as the Mapping.