...Display Coordinates as they are Transformed

In addition to formatting coordinates as part of a program's output, you may also want to examine coordinate values while debugging your program. To save time, you can “eavesdrop” on the coordinate values being processed every time they are transformed. For example, when using the FrameSetFrameSet pointer “wcsinfo” obtained in §3.4 to transform coordinates (§3.7), you could inspect the coordinate values as follows:


\begin{terminalv}
astSet( wcsinfo, ''Report=1'' );
astTran2( wcsinfo, N, xpixel, ypixel, 1, xworld, yworld );
\end{terminalv}

By setting the FrameSet's ReportReport attribute to 1, coordinate transformations are automatically displayed on the program's standard output stream, appropriately formatted, for example:


\begin{terminalv}
(42.1087, 20.2717) --> (2:06:03.0, 34:22:39)
(43.0197, 21.1705...
...:24:23.1, 43:32:41)
(50.2742, 28.4499) --> (2:26:40.6, 44:41:27)
\end{terminalv}

For a complete description of the Report attribute, see its entry in Appendix C. For further details of how to set and enquire attribute values, see §4.6 and §4.5.