iraf.net

I'm currently attempting to use the IRAF task dohydra in order to reduce SparsePak data. The task is able to get past the flat field fitting, but encounters an error. I believe this occurs when arcrefs gives a faulty extension. The task looks for a .iraf.ms file, which I am unfamiliar with and epar arcrefs reveals a blank input, so it must be coming from another input. Does anyone have previous experience with this error? The error report below gives the parameters of arcrefs. The parameters I use for dohydra is below the error report.

Create response function FullFlatsparsepak.iraf.ms
Extract flat field FullFlat
Fit and ratio flat field FullFlat
Create the normalized response FullFlatsparsepak.iraf.ms
Extract arc reference image a106
Determine dispersion solution for a106
ERROR: Cannot open file (database/ida106sparsepak.iraf.ms)
"plotfile=plotfile, logfiles=logfile, verbose=yes)"
line 179: srcfibers$arcrefs.cl (hidden task)
called as: `arcrefs (arcref1=a106, arcref2=, extn=sparsepak.iraf.ms, arcreplace=, apidtable=sparsepak.iraf, response=FullFlatsparsepak.iraf.ms, crval=INDEF, cdelt=INDEF, done=tmp$iraf1184wa, log1=logfile, log2=dev$null)'
"crval, cdelt, done, log1, log2)"
line 393: srcfibers$proc.cl (hidden task)
called as: `proc (objects=@targetlist, apref=FullFlat, flat=FullFlat, throughput=, arcs1=a106.fits, arcs2=, arcreplace=, arctable=, fibers=82, apidtable=sparsepak.iraf, crval=INDEF, cdelt=INDEF, objaps=, skyaps=, arcaps=, objbeams=0,1, skybeams=0, arcbeams=, scattered=no, fitflat=yes, recenter=no, edit=no, trace=no, arcap=no, clean=no, dispcor=yes, savearcs=no, skyalign=no, skysubtract=no, skyedit=yes, saveskys=no, splot=yes, redo=yes, update=yes, batch=no, listonly=no)'
"skyedit, saveskys, splot, redo, update, batch, listonly)"
line 69: hydra$dohydra.cl
called as: `dohydra (mode=h)'

PACKAGE = hydra
TASK = dohydra

objects = @targetlist List of object spectra
(apref = FullFlat.fits) Aperture reference spectrum
(flat = FullFlat.fits) Flat field spectrum
(through= ) Throughput file or image (optional)
(arcs1 = a106.fits) List of arc spectra
(arcs2 = ) List of shift arc spectra
(arcrepl= ) Special aperture replacements
(arctabl= ) Arc assignment table (optional)

(readnoi= 3.40) Read out noise sigma (photons)
(gain = 0.219) Photon gain (photons/data number)
(datamax= INDEF) Max data value / cosmic ray threshold
(fibers = 82) Number of fibers
(width = 5.) Width of profiles (pixels)
(minsep = 5.) Minimum separation between fibers (pixels)
(maxsep = 10.) Maximum separation between fibers (pixels)
(apidtab= sparsepak.iraf) Aperture identifications
(crval = INDEF) Approximate central wavelength
(cdelt = INDEF) Approximate dispersion
(objaps = ) Object apertures
(skyaps = ) Sky apertures
(arcaps = ) Arc apertures
(objbeam= 0,1) Object beam numbers
(skybeam= 0) Sky beam numbers
(arcbeam= ) Arc beam numbers

(scatter= no) Subtract scattered light?
(fitflat= yes) Fit and ratio flat field spectrum?
(clean = no) Detect and replace bad pixels?
(dispcor= yes) Dispersion correct spectra?
(savearc= no) Save simultaneous arc apertures?
(skyalig= no) Align sky lines?
(skysubt= no) Subtract sky?
(skyedit= yes) Edit the sky spectra?
(savesky= no) Save sky spectra?
(splot = yes) Plot the final spectrum?
(redo = yes) Redo operations if previously done?
(update = yes) Update spectra if cal data changes?
(batch = no) Extract objects in batch?
(listonl= no) List steps but don't process?

(params = ) Algorithm parameters
(mode = ql)

Hi Kem,

This is a gotcha that people encounter at times. It has to do with allowing the task to work with different image formats (e.g. imh remember that? ). Its been so long that I could not find a previous answer. But here is what the help page has:



So set imtype to be the extension of the format you are using. If this doesn't work send me and what extension your files have.

Regards,
Frank

I have only .fits files for my arcs, darks, flats, science exposures from the telescope, and I have imtype set as .fits in my login.cl file. To verify, I used your command to make sure it was reading the login.cl file correctly and it is.

Let's look at the error message. The immediate failure is not finding database/ida106sparsepak.iraf.ms. So what is in the database subdirectory? Is there an idap106* file? If not did you properly exit the dispersion function fitting such that an output was written? Or is there an idap106 file but without the sparsepak.iraf part? The logic of the task is to allow for different .iraf files by tacking on the name. Maybe it is messing up in doing this. So first I need to understand what is in the database directory. Could you please copy and paste the contents of this directory? From that I'll continue working through the code to understand how you got to the point where it is looking for the arc reference solution but not finding it.

Frank

BTW the .iraf file is an anacronism from the very early days of hydra. Now the information in the .iraf file should also be in the header. So if the header contains keywords (I forget the root part but it should be obvious) then instead of putting sparsepak.iraf in the apidtable parameter you can put an image that contains the matching fiber configuration. For sparsepak, which I've not had any experience with, I assume the configuration is always the same.

Anyway, either way should work but the problem is involving use of the apidtable parameter.

Frank

Here's the contents of /database before and after a dohydra run. The failure is occurring after I hit q to exit the plotting window when it attempts to find the dispersion solution.

Before an attempt at dohydra:


After an attempt at dohydra:


After reading your second post, I tested to see what would happen if I put sparsf as the apidtab to match the file name structure which I have. Iraf complained about not having a sparsf file, but was able to run through the process for the first time and attribute wavelengths which I expected though I don't know whether to trust it or not given I just made up an apidtab name. I didn't really see anything in my file headers to give a clearer hint. It looks like dohydra will always add the apidtab input to the file name structure of the files it uses during the dispersion solution step. After this run I just described,

To clarify, the HomeLacos file that shows up in /database is expected. It's the "home" location science exposure which has been gone through LA Cosmic prior to the dohydra treatment.