Making transformation of coordinates: the FITCOORDS task

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Making transformation of coordinates: the FITCOORDS task

The FITCOORDS task determines the user coordinates from the data produced with the IDENTIFY and REIDENTIFY tasks.

The dispersion solution is theoretically represented by Eq. 3 for an ideal case. The transformation function in the dispersion direction (X) can be set to a fourth or fifth order function in IRAF³.

A slit image is represented by a parabolic function as explained in § 2.4. The transformation function in the spatial direction (Y) can be set to a third order equation or second order equation in IRAF if the curvatures of slit images are negligible.

**Figure 42:** An example of the parameter setting and execution results of the FITCOORDS task.
$\begin{figure} \lq \begin{alltt} \relax{} {\footnotesize >lpar fitcoor... ... = 14620.88 (1024, 71) = 14991.41 } \relax \end{alltt} \end{figure}$

Footnotes

... IRAF ³: In IRAF, the order of an equation means the number of terms in it.

Tae-Soo Pyo
2003-05-29