iraf.net

I am trying to use splot to look at spectra.
There are a few things that I haven't figured out how to do:
for example when I run:splot image1.fit

1) its default is to display a graphic of a single [i:b4b05afa20]column[/i:b4b05afa20] of the image, with the particular column to be displayed decided by the parameter 'line' ie. line=100 displays the graphic of column=100 - what is the name of the parameter that allows to toggle between rows and columns, and what is the value that this parameter must have assigned to it?
2) There are certain things that I have seen done such as averaging over a certain number of columns and then subtracting from yet another column, for example to subtract the sky from the spectra of interest -For example to average over columns 100-200, I think the command is something like:
:c 100 200
However, I have tried this within the Irafterm and I have the following error returned:
'unrecognised or ambiguous command'
so what is correct procedure?
Also, what is the command to subtract the average over all these columns from yet another column?
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I've realised it was implot not splot that was the task I was thinking of.
Have figured out how to do everything I queried in the last post except:How can I subtract the average of a number of columns (sky background) from my aperture column?

Hello,Your last post ended with:[quote:97ae8a881b]How can I subtract the average of a number of columns (sky background) from my aperture column?[/quote:97ae8a881b]Do you still need an answer? Do you mean from within SPLOT or in general with the data files? I am guessing you have a longslit image. There are many ways to do what you ask but it depends on the nature of the data. In particular, this type of function (sky subtraction in an aperture) is one of the main things done by the APEXTRACT (aperture extraction) package in a variety of ways.Frank Valdes

Thanks for your reply.I did indeed manage to figure it out and so no longer need an answer.