next up previous contents
Next: The Classification Up: Procedures to Follow Previous: Helpful Hints

In Case of Trouble

It may happen that program execution is aborted or that the output is clearly wrong. In most cases it is caused by setting wrong values for keywords. Check carefully whether keyword values look reasonable. If there is no obvious mistake made in setting the keywords, run the ANALYSE/INV program again using the DEBUG option. This can be done by using DEBUG as one of the parameters of the ANALYSE/INV command line. A lot of information will be displayed for each object. It is possible to follow the program flow and to see how the cleaning of blended images is done. Because of the large amount of information displayed, using the DEBUG option is feasible only for very small frames. Identify on the image display the region which gives most of the trouble such as not detecting obvious objects, failure to resolve pairs, or multiple detections of single objects, and use the EXTRACT command to create a subframe of dimensions between $50\times50$ and $150\times150$ pixels with up to $10\ldots20$ objects. Then use the command SEARCH/INV and finally ANALYSE/INV with the DEBUG option and try to find out, based on the displayed data, what the source of the trouble is. Displaying data concerning a particular object starts with its identification number, and its pixel coordinates. Next comes three kinds of information, each consisting of 80 values. They are arranged in eight columns. The first presents a profile in eight octants. Each column corresponds to a particular octant, starting with an octant pointing to the right and going counter clockwise. The first row gives the value of the central point. The second kind of 80-values array uses only four first columns. The first column gives average profile, the next three give the first three amplitudes of Fourier expansion of the objects profile over the octants. In both these cases data has been divided by background and multiplied by 1000 for easier management of displays. The third kind of an array contains only 0 and 1. This array indicates how the object was cleaned. The value of 0 indicates that the actual data is used. The value of 1 means that the data is interpolated. The arrangement of columns and rows is the same as in the case of displaying the profile. Only the row corresponding to the central point is missing. After intermediate data is displayed for all objects, the final results are shown. They are presented in three separate chunks of data for each object. The first gives ID, x-coordinate, y-coordinate, distance to nearest other object, extent of unblended central part, approximate radius of an object, and radius of saturated part of an image, all except ID expressed in pixels. The second gives data that is stored in an output table. A list of table column numbers and labels can be used for identifying displayed quantities. Data from columns :IDENT, :NR_OTH_OBJ, and :AR is not presented here, as it has been previously displayed. The third gives first 21 points of one-dimensional profile.


next up previous contents
Next: The Classification Up: Procedures to Follow Previous: Helpful Hints
http://www.eso.org/midas/midas-support.html
1999-06-15