irafil and rtextimage problem
zshi wrote on May 26, 2009
Hi irafers,
I'm trying to import my CCD data into IRAF. I've work it out with 1D spectra files using rspectext. However when it comes to 2D CCD data, I've tried to use irafil and rtextimage. And Both methods can't give me the correct result.
for rtextimage, I type as follows,
ecl>rtextimage Xe.asc output=1 header- pixels+ dim=2048,2048
for irafil, I type,
ecl>irafil xe.dat 2048 2048
Both command lines give me result, however the result seems wrong. It's not the same as shown in original program.
Do I use the command in a right way? Or Is there something particular should I pay attention to when I import data?
Thanks a lot for your time and advice~
I'm trying to import my CCD data into IRAF. I've work it out with 1D spectra files using rspectext. However when it comes to 2D CCD data, I've tried to use irafil and rtextimage. And Both methods can't give me the correct result.
for rtextimage, I type as follows,
ecl>rtextimage Xe.asc output=1 header- pixels+ dim=2048,2048
for irafil, I type,
ecl>irafil xe.dat 2048 2048
Both command lines give me result, however the result seems wrong. It's not the same as shown in original program.
Do I use the command in a right way? Or Is there something particular should I pay attention to when I import data?
Thanks a lot for your time and advice~
Mike Fitzpatrick wrote on May 26, 2009
It's hard to say what might be wrong unless you can define "seems wrong" better. The 'otype' parameter sets the output type, are you perhaps truncating floating point values to short/int? Otherwise the only thing that looks wrong is "output=1", in general using a number for an image name can lead to problems, try "output=img001" or somesuch.
Is it the displayed image that looks 'wrong' (how??) or does IMSTAT show the pixel values are seriously wrong?
-Mike
Is it the displayed image that looks 'wrong' (how??) or does IMSTAT show the pixel values are seriously wrong?
-Mike
zshi wrote on May 26, 2009
Hello Mike,
3x for your reply.
I use "imstat" to examine my output fits file. It shows the minimum number is 0,which in my case is impossible, and the maximum number is right. Seems like iraf takes something as zero.
When I converted dev$pix into text file, I find the data end with a ".", like "35.". Should I add dot to every element?
3x for your reply.
I use "imstat" to examine my output fits file. It shows the minimum number is 0,which in my case is impossible, and the maximum number is right. Seems like iraf takes something as zero.
When I converted dev$pix into text file, I find the data end with a ".", like "35.". Should I add dot to every element?
Mike Fitzpatrick wrote on May 26, 2009
Does the image look reasonable if you display it? If there aren't as many pixels in the file as you give for the dimensions you'll end up with zero values, and perhaps also a skewed image or a band of blank pixels. Note the unix 'wc' command can give you a count of words in a file, if you have just ascii pixel values that number should match your dimensions. You don't need to explicitly put a period on the values, unless you have "strange" representations of the numbers it should pick out the type and set it appropriately.
If you still have problems upload the ascii file to the anonftp at ftp://iraf.noao.edu/pub and I'll have a look.
-Mike
If you still have problems upload the ascii file to the anonftp at ftp://iraf.noao.edu/pub and I'll have a look.
-Mike
Last post on May 26, 2009