Thursday, July 26, 2007

Multiple output files

If one wants to write out multiple fits files at a time which have same inname and inclass just different inseq no. how does one do that?

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Wednesday, July 25, 2007

limited line length in runfiles

in runfiles you can't have lines longer than ~70 characters (i'm not sure what the actual limit is). i've only had a problem with this once when i was defining a large array of filenames for the multiple pointings in a mosaic. the only way to get the whole array defined was to fill in the last three entries manually. i've posted the code i used below.

string*8 obj_name(15)
obj_name = 'GH40-1','GH40-2','GH40-3','GH40-4','GH40-5','GH40-6'
obj_name(7) = 'GH40-7'
obj_name(8) = 'GH40-8'
obj_name(9) = 'GH40-9'

Note added by Amanda on 10/05/07: It's actually easier to use the tilde. See this post.

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Thursday, July 5, 2007

SMOTH and and regridding

Can anyone suggest an AIPS task that can help me with the following? I'm looking at emission lines in a diffuse source. I needed to try and increase my S/N levels, but could not smooth the line because it has some complicated structure (multiple velocity components, etc) that I want to fit. So, I smoothed spatially using SMOTH.

Since my beam is now almost twice the size that it used to be (6'' instead of 4'') I think the pixel size of the original image may be oversampling the beam. Can I regrid the smoothed image to have 1'' pixels instead of 0.5'' pixels? How?


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Wednesday, July 4, 2007

Gaussian Fitting

Here is a request from an anonymous reader; any advice, anyone?

Can you please help me with the following? I have an image with 5 substructures in it. The peaks inthe image decrease in size from left to right, the leftmost two are the brightest. All of them are close to each other. With AIPS jmfit I can fit not more than 4 gaussians. I played around a bit and noticed that dividing the whole image into two parts and fitting 2 gaussians and 3 gaussians respectively in the two parts does not work properly and gives a bad fit. So I came up with this idea. I can first fit four gaussians to first four peaks, and then from the whole image subtract the brightest two. To the residual image now I fit 3 gaussians. I checked whether this technique gives me a good fit to a slice of data (Wrote my own fortran programs for that). It seems to work but my problem is how to do it in aips.

So my problem is the following. I want to fit 4 gaussians to a selected range of data. Then subtract only the brightest two gaussian from the whole image. Then fit other three gaussians to another restricted part of the data. Could anyone please help me on this?

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