Question!!

leocastaneda wrote on Jun 17, 2007

Good Morning!!!
I am using IRAF for surface photometry. I need to get photometry for some
slits directons on my fits files. For this task I have an IRAF script, but
I have a real problem:

The data that I have to use in some iraf task as imstat are storaged in
strings, they are real values but the format are strings, I need to recover the
REAL value from the string, in order to be able to use in different tasks.
Can you help me with it?

Best regards,

Leonardo
AIFA Bonn
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Mike Fitzpatrick wrote on Jun 17, 2007

If I understand your question, you have a text file of values you want to convert to an image so you can use tasks like IMSTAT? If so, see the RTEXTIMAGE task to convert to a FITS file. If the values aren't really representative of an image but simply a table of values, you can use the TABLES external package (needs to be installed separately) to do the same, e.g. the TSTAT task in the TTOOLS package.

Cheers,
-Mike

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Mike Fitzpatrick wrote on Jun 17, 2007

Thanks a lot for your answer. May be the question was not enough clear.
My question is as follows:
I have two arrays x[(i)],y[(i)] generated by a cl script. They are positions on m y fits files, actually I am fitting slits with it, it means x[(i)],y[(i)] are pairs as (200,500) for example, but after this fitting I need to use the coordinates in dome iraf tasks as
imstat (image=image//"[x:y,x[j]:y[(j)]]") and x[(i)],[y(i)] are formally STRINGS variables and the tasks need REAL values, the question is how I can go from strings to real vaues of my coordinates. </blockquote>

What you need to do in this case is to create an image section based on the values, e.g. "image[200:500,200:500]". Note this is different than simply the pixel value at location (200,500) but makes more sense for calling IMSTAT. In any case, you would use the '//' string concatenation operator as in

string sec = image // "[" // x[i] // ":" // y[i] // "," // x[i] // ":" // y[i] // "]"
imstat(images=sec, .....)

Let me know if I still don't understand the question.

Cheers,
-Mike </div> --- *Last post on Jun 17, 2007*