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I have problems with sensfunc. When I run sensfunc, I got the following message: >sensfunc
Input standard star data file (from STANDARD) (std): std
Output root sensitivity function imagename (sens): sens
ERROR: No degrees of freedom
Here my std file:[chr7596_01.ms] 1 2031 20.00 1.123 60.000 2090.000 HR 7596I have iraf V2.14. I am pasting the standard and sensfunc parameters below.
I also tried with order 3 in sensfunc, but the problem is the same.I hope you can help me.
Thanks
Julio
PACKAGE = onedspec
TASK = standard
input = "chr7596_01.ms" Input image file root name
output = "std" Output flux file (used by SENSFUNC)
star_name = "hr7596blue" Star name in calibration list
airmass = Airmass
exptime = Exposure time (seconds)
mag = Magnitude of star
magband = Magnitude type
teff = Effective temperature or spectral type
answer = "no" (no|yes|NO|YES|NO!|YES!)
(samestar = yes) Same star in all apertures?
(beam_switch = no) Beam switch spectra?
(apertures = "") Aperture selection list
(bandwidth = INDEF) Bandpass widths
(bandsep = INDEF) Bandpass separation
(fnuzero = 3.6800000000000E-20) Absolute flux zero point
(extinction = "onedstds$ctioextinct.dat") Extinction file
(caldir = "onedstds$spec16cal/") Directory containing calibration data
(observatory = )_.observatory) Observatory for data
(interact = yes) Graphic interaction to define new bandpasses
(graphics = "stdgraph") Graphics output device
(cursor = "") Graphics cursor input
(mode = "ql")
PACKAGE = onedspec
TASK = sensfunc
standards = "std" Input standard star data file (from STANDARD)
sensitivity = "sens" Output root sensitivity function imagename
answer = "yes" (no|yes|NO|YES)
(apertures = "") Aperture selection list
(ignoreaps = yes) Ignore apertures and make one sensitivity function?
(logfile = "logfile") Output log for statistics information
(extinction = "onedstds$ctioextinct.dat") Extinction file
(newextinctio = "extinct.dat") Output revised extinction file
(observatory = )_.observatory) Observatory of data
(function = "legendre") Fitting function
(order = 5) Order of fit
(interactive = yes) Determine sensitivity function interactively?
(graphs = "sr") Graphs per frame
(marks = "plus cross box") Data mark types (marks deleted added)
(colors = "2 1 3 4") Colors (lines marks deleted added)
(cursor = "") Graphics cursor input
(device = "stdgraph") Graphics output device
(mode = "ql")

Hi,The error message is an interpretation of the result of attempting a least square fit. Specifically the least square matrix cannot be inverted. In any case this error can only mean there is something wrong with the input data such as large gaps or too few fitting points for the desired function order. To help further I would either want to see the graph produce when running sensfunc or the actual data being used by sensfunc. In the latter case you can attach it to a mail to me (valdes@noao.edu) or put it somewhere that I can retrieve it.Frank Valdes