Calculate ellipses that describe a galaxy using iraf

This workflow calculate the ellipses that better match a galaxy by doing to iterations. In the first one the center and the outer ellipse are aproximated because there might be bars that affect to the inner ellipses. In the second one, files with the ellipse data are built. It creates ellipse scripts using data from a votable, it runs ellipse, its results are added to the votable, it creates new scripts for ellipse using the previous results, it runs ellipse a second time and it finally includes the results into the votable. It requires the specification of the columns that contain file names (these files should be accesibles from taverna). Scripts are created (one for every row in the votable) using a template whose keys are replaced by data from a votable. Keys must appear also in the vocabulary file and match column names in the votable. It uses, pyraf (ellipse task), astrotaverna plugin (http://wf4ever.github.com/astrotaverna/).