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Hello,
I have a problem with the output file obtained from using "continuum".
The following is the steps I followed for 1-D spectra of a cross-correlation
star, oPeg.on> epar continuum
<type=ratio, wavescale=no, override=no, listonl=no, etc.>on> continuum image flattenedimage
<I got the curve I wanted and even a hardcopy of it and it was just right.>on> splot flattenedimage
<I got a lot of verticle lines (something resembling two different bar codes,
one on top of the other) with the vertical axis scaled from 0 to 1 and the
horizontal axis scaled from 0 to 800 pixels (like the original image of the
star).>I thought I was supposed to get an output file that resembled my original image
but with a flattened continuum. Should I change the parameters of continuum or
splot, and should I do something particular during the interactive part of
continuum?Thank You,
Cynthia Sexton
csexton@csci0.uark.edu

Hello Cynthia,Let me take a guess. What I think happened is that your original
image is of integer type. CONTINUUM is then producing the same
output type. But, of course, if you continuum normalize to numbers
between 0 and near 1 and then truncate them to integer you will get
either 0, 1, or 2. When plotted you will get an graph much as
you describe. This inappropriate behavior of CONTINUUM has been
changed for the next IRAF; i.e. it will always output real valued
data regardless of the input. The solution is for you to first
change the data type of the original image with CHPIXTYPE; you
can either do it "in place" or create a different image.Let me know if this is not the solution to this problem.Cheers,
Frank