how to pick specific range of wavelength
Andreas Liudi Mulyo wrote on May 29, 2010
dear all iraf user,
right now, i am doing my research in line spread function topic. in order to do that, as usual, i was reducing until it was found spectrum of calibration lamp, and it was work. From my supervisor's advice, i have to pick specific range of wavelength and as we know, most of spectrum calibration lamp is Gaussian profile and it has many (at least we see 2) Gaussian profile, let say from 400 nm - 800 nm.
Now, i want to pick specific wavelength (one gaussian profile). i have looked up in iraf package (apall parameter and splot parameter), but i can't find it.
Any help would be appreciate.
Thank you
Regards
Andreas
===============
Engineering Physics Student
Photonics Laboratory
Sepuluh Nopember Institute of Technology
Indonesia
right now, i am doing my research in line spread function topic. in order to do that, as usual, i was reducing until it was found spectrum of calibration lamp, and it was work. From my supervisor's advice, i have to pick specific range of wavelength and as we know, most of spectrum calibration lamp is Gaussian profile and it has many (at least we see 2) Gaussian profile, let say from 400 nm - 800 nm.
Now, i want to pick specific wavelength (one gaussian profile). i have looked up in iraf package (apall parameter and splot parameter), but i can't find it.
Any help would be appreciate.
Thank you
Regards
Andreas
===============
Engineering Physics Student
Photonics Laboratory
Sepuluh Nopember Institute of Technology
Indonesia
Andreas Liudi Mulyo wrote on May 29, 2010
anyone can help me?
i do really need your suggestions.. i don't have any hint to solve this problem..
i just can display spectrum after i edit its aperture with "apall", identify its spectrum with "identify" and display it with "splot". When i did that, i found the spectrum was still in pixel, although i have identified it. When i identified back, i found no mistake, it had already with Angstroms.
With splot, i can plot xmin and xmax, but still, in pixel, but i need in Angstroms. I have tried to read manual in identify task, but i can't find something useful.
I need your advice. Thank you in advance.
Regards
Andreas
i do really need your suggestions.. i don't have any hint to solve this problem..
i just can display spectrum after i edit its aperture with "apall", identify its spectrum with "identify" and display it with "splot". When i did that, i found the spectrum was still in pixel, although i have identified it. When i identified back, i found no mistake, it had already with Angstroms.
With splot, i can plot xmin and xmax, but still, in pixel, but i need in Angstroms. I have tried to read manual in identify task, but i can't find something useful.
I need your advice. Thank you in advance.
Regards
Andreas
James Turner wrote on May 29, 2010
Hi Andreas,
I had trouble understanding your first question, but in your second post I think you're saying that you don't see world co-ordinates in splot after running identify. You may need to run "dispcor" or "transform" to write the WCS keywords to the header (as opposed to a database file). Notice the "SEE ALSO" section at the bottom of the identify help page and the IRAF spectroscopy user's guides located here:
http://iraf.noao.edu/docs/spectra.html
Hope that helps.
Cheers,
James.
I had trouble understanding your first question, but in your second post I think you're saying that you don't see world co-ordinates in splot after running identify. You may need to run "dispcor" or "transform" to write the WCS keywords to the header (as opposed to a database file). Notice the "SEE ALSO" section at the bottom of the identify help page and the IRAF spectroscopy user's guides located here:
http://iraf.noao.edu/docs/spectra.html
Hope that helps.
Cheers,
James.
Andreas Liudi Mulyo wrote on May 29, 2010
Hi jturner,
That's what i mean, i don't see world co-ordinates in splot after i running identify. That was frustating, i repeat this step over 10 times and it still in pixel. Ok, i will try your suggestion too.
There is a process that i don't understand. In "apall" task, there is a situation when i have to find rms value as small as possible. To do that, i can change its function (spline3, chebyshev, legendre and spline5) or change the order.
I wonder if i can see the function of its profile, in mathematically. Is it possible?
Thank you in advance
Regards
Andreas
That's what i mean, i don't see world co-ordinates in splot after i running identify. That was frustating, i repeat this step over 10 times and it still in pixel. Ok, i will try your suggestion too.
There is a process that i don't understand. In "apall" task, there is a situation when i have to find rms value as small as possible. To do that, i can change its function (spline3, chebyshev, legendre and spline5) or change the order.
I wonder if i can see the function of its profile, in mathematically. Is it possible?
Thank you in advance
Regards
Andreas
James Turner wrote on May 29, 2010
i repeat this step over 10 times and it still in pixel.
I think that's because identify is just writing to a database until you do dispcor/transform. Anyway, if it doesn't work the first time, it probably won't work the 10th :-).
I wonder if i can see the function of its profile, in mathematically. Is it possible?
Yes, press 'f' in the identify plot to see the fit and h/j/k/l to change what's plotted (also see the help page).
James.
Andreas Liudi Mulyo wrote on May 29, 2010
hi jturner,
when i tried to dispcor on my images, ap_c1, the result is:
Warning: Cannot open file (database/ecap_c1_ga)
Warning: Cannot open file (database/idap_c1_ga)
Warning: ap_c1: Dispersion data not found
Then i tried transform, the result is similar like above,
ERROR: Cannot open file (database/fcWarmWhiteFl.data)
What should i do?
I have press "f" in the identify plot and i didn't see any matematical function output, just like lines coming up. What that means? I have read help page, but it wasn't help me very much. Any suggestions?
Thank you
when i tried to dispcor on my images, ap_c1, the result is:
Warning: Cannot open file (database/ecap_c1_ga)
Warning: Cannot open file (database/idap_c1_ga)
Warning: ap_c1: Dispersion data not found
Then i tried transform, the result is similar like above,
ERROR: Cannot open file (database/fcWarmWhiteFl.data)
What should i do?
I have press "f" in the identify plot and i didn't see any matematical function output, just like lines coming up. What that means? I have read help page, but it wasn't help me very much. Any suggestions?
Thank you
Andreas Liudi Mulyo wrote on May 29, 2010
hi jturner,
when i tried to dispcor on my images, ap_c1, the result is:
Warning: Cannot open file (database/ecap_c1_ga)
Warning: Cannot open file (database/idap_c1_ga)
Warning: ap_c1: Dispersion data not found
Then i tried transform, the result is similar like above,
ERROR: Cannot open file (database/fcWarmWhiteFl.data)
What should i do?
I have press "f" in the identify plot and i didn't see any matematical function output, just like lines coming up. What that means? I have read help page, but it wasn't help me very much. Any suggestions?
Thank you
when i tried to dispcor on my images, ap_c1, the result is:
Warning: Cannot open file (database/ecap_c1_ga)
Warning: Cannot open file (database/idap_c1_ga)
Warning: ap_c1: Dispersion data not found
Then i tried transform, the result is similar like above,
ERROR: Cannot open file (database/fcWarmWhiteFl.data)
What should i do?
I have press "f" in the identify plot and i didn't see any matematical function output, just like lines coming up. What that means? I have read help page, but it wasn't help me very much. Any suggestions?
Thank you
James Turner wrote on May 29, 2010
andreas
Warning: Cannot open file (database/ecap_c1_ga)
Warning: Cannot open file (database/idap_c1_ga)
Warning: ap_c1: Dispersion data not found
That means it's not finding the results from identify for your input file. Either you need to run identify beforehand on the same file in the same directory or you need to specify a matching reference file that you've already run identify on, by setting REFSPEC1 in the input file header, eg. with the task refspectra (see the second manual on the page I sent a link for).
I have press "f" in the identify plot and i didn't see any matematical function output, just like lines coming up. What that means?
Not sure; I have never seen that happen.
Cheers,
James.
Andreas Liudi Mulyo wrote on May 29, 2010
jturner
Yes, press 'f' in the identify plot to see the fit and h/j/k/l to change what's plotted (also see the help page).
James.
I don't really understand what it means. Can you explain?
No, i mean if there is a parabolic graph in identify plot for example. Then i can see the mathematical function of parabolic graph, let say y=x^2+10.
Can IRAF do that?
Last post on May 29, 2010