help on stsdas.analysis.isophote ellipse task
Kati1224 wrote on Jul 08, 2008
I have been trying to use ellipse to perform galaxy subtraction on a set of WFPC2 images on a Linux computer. Everytime I attempt to run it in interactive mode the application automatically loads a mask that covers the entire image. I don't have any mask files so I'm not sure why it is doing this, but I've tried practically everything. I've changed various parameters and even tried on different images and it still doesn't work properly.
Please help!
Kati
Please help!
Kati
Mike Fitzpatrick wrote on Jul 08, 2008
Try unlearning the DISPLAY task -- This is used internally by ELLIPSE to display the image but has parameters for overlaying masks that you may be using unintentionally.
-Mike
-Mike
Kati1224 wrote on Jul 08, 2008
Thanks for the suggestion, but it didn't work.
The program starts loading, and it asks me to find the center, but before I can do anything, it immediately continues running and loads the pixel mask:
isophote> ellipse image01.fits[0] test.tab
Running object locator... Done.
Can not find object. Please, use
`x' cursor key to mark galaxy center, and
next `f' key to fit.
Loading display with pixel mask...
#
# Semi- Isophote Ellipticity Position Grad. Data Flag Iter. Stop
# major mean Angle rel. code
# axis intensity error
#(pixel) (degree)
#
ERROR: No meaningful solution.
And then it covers my image with a big red mask that I can't get rid of. I just started using IRAF on this computer, so all of the parameters should be set to their defaults.
The program starts loading, and it asks me to find the center, but before I can do anything, it immediately continues running and loads the pixel mask:
isophote> ellipse image01.fits[0] test.tab
Running object locator... Done.
Can not find object. Please, use
`x' cursor key to mark galaxy center, and
next `f' key to fit.
Loading display with pixel mask...
#
# Semi- Isophote Ellipticity Position Grad. Data Flag Iter. Stop
# major mean Angle rel. code
# axis intensity error
#(pixel) (degree)
#
ERROR: No meaningful solution.
And then it covers my image with a big red mask that I can't get rid of. I just started using IRAF on this computer, so all of the parameters should be set to their defaults.
Mike Fitzpatrick wrote on Jul 08, 2008
Sorry, but unless you get another response from somebody who is more familiar with the task I might suggest you contact the STScI helpdesk (help@stsci.edu) for help. My guess would be that the 'no meaningful solution' is important and might cause the task to consider the entire image the mask, but I don't really know how the task works and whether the mask is a property of the image or the derived solution.
In any case, check your parameters and the 'test.tab' file for anything suspicious.
Good luck,
-Mike
In any case, check your parameters and the 'test.tab' file for anything suspicious.
Good luck,
-Mike
Last post on Jul 08, 2008