ast: Provide defaults for keywords CNPIX1/2 when reading a DSS header

Requested by Bill Joye.
Starlink · Aug 10, 2012 · b0ac6b0 · b0ac6b0
1 parent 42e1edd
commit b0ac6b0
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Showing 3 changed files with 15 additions and 3 deletions.
diff --git a/libraries/ast/ast.news b/libraries/ast/ast.news
@@ -16,9 +16,11 @@ environment-independent.
 Main Changes in this Version
 ----------------------------
 
-A bug has been fixed in astRebinSeq<X> which could result in
+- A bug has been fixed in astRebinSeq<X> which could result in
 incorrect normalisation of the final binned data and variance values.
 
+- When reading a FrameSet from a FITS-DSS header, the keywords CNPIX1 and
+CNPIX2 now default to zero if absent. Previously an error was reported.
 
 Main Changes in V7.0.5
 ----------------------

diff --git a/libraries/ast/fitschan.c b/libraries/ast/fitschan.c
@@ -1040,6 +1040,9 @@ f     - AST_WRITEFITS: Write all cards out to the sink function
 *        for pointing out this error).
 *     8-AUG-2012 (DSB):
 *        Correct assignment to lonpole within CLASSFromStore.
+*     10-AUG-2012 (DSB):
+*        Default DSS keywords CNPIX1 and CNPIX2 to zero if they are
+*        absent, rather than reporting an error.
 *class--
 */
 
@@ -8472,9 +8475,13 @@ static void DSSToStore( AstFitsChan *this, FitsStore *store,
 /* Check the inherited status. */
    if( !astOK ) return;
 
+/* Get the optional DSS keywords, supplying defaults for any missing keywords. */
+   cnpix1 = 0.0;
+   cnpix2 = 0.0;
+   GetValue( this, "CNPIX1", AST__FLOAT, &cnpix1, 0, 1, method, class, status );
+   GetValue( this, "CNPIX2", AST__FLOAT, &cnpix2, 0, 1, method, class, status );
+
 /* Get the required DSS keywords. Report an error if any are missing. */
-   GetValue( this, "CNPIX1", AST__FLOAT, &cnpix1, 1, 1, method, class, status );
-   GetValue( this, "CNPIX2", AST__FLOAT, &cnpix2, 1, 1, method, class, status );
    GetValue( this, "PPO3", AST__FLOAT, &ppo3, 1, 1, method, class, status );
    GetValue( this, "PPO6", AST__FLOAT, &ppo6, 1, 1, method, class, status );
    GetValue( this, "XPIXELSZ", AST__FLOAT, &xpixelsz, 1, 1, method, class, status );

diff --git a/libraries/ast/sun_master.tex b/libraries/ast/sun_master.tex
@@ -22732,6 +22732,9 @@ \subsection{\xlabel{changes}\xlabel{list_of_most_recent_changes}Changes
 \item A bug has been fixed in astRebinSeq<X> which could result in
 incorrect normalisation of the final binned data and variance values.
 
+\item When reading a FrameSet from a FITS-DSS header, the keywords CNPIX1
+and CNPIX2 now default to zero if absent. Previously an error was reported.
+
 \end{enumerate}