From aa9d3cd806e7f093abafb2e2e8665f6e4ddb2287 Mon Sep 17 00:00:00 2001 From: David Berry Date: Tue, 9 Jan 2018 14:06:09 +0000 Subject: [PATCH] Complete docs for previous change to astLinearApprox --- ast.news | 7 +++++++ sun_master.tex | 8 ++++++++ 2 files changed, 15 insertions(+) diff --git a/ast.news b/ast.news index dcb2445a..cbefd459 100644 --- a/ast.news +++ b/ast.news @@ -25,6 +25,13 @@ the SipOK attribute of the FitsChan is set to a non-zero value (which is the default), and the FrameSet being written out contains an appropriate PolyMap that conforms to the requirements of the SIP convention. +- The behaviour of the astLinearApprox method of the Mapping 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. Main Changes in V8.6.1 diff --git a/sun_master.tex b/sun_master.tex index 91b55744..cfa6c431 100644 --- a/sun_master.tex +++ b/sun_master.tex @@ -21843,6 +21843,14 @@ \subsection{\xlabel{changes}\xlabel{list_of_most_recent_changes}Changes \begin{enumerate} +\item The behaviour of the astLinearApprox method of the Mapping 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. + \item The astWrite method of the FitsChan 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