...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.