sedFit Information (Terms & Conditions)
It is important to note right away this is proprietary, unreleased software, with Caltech scientist Andy Boden as the author and principal investigator for sedFit. As such, at the present, any scientific efforts that result from use of sedFit entitle Andy to right of authorship as a minor contributing author. For these efforts involving PTI and CHARA, however, Andy has expressed a specific interest in supporting these scientific investigations with sedFit (noting this condition).

Useful link: the Lowell LARI-BGBF sedfit wiki

what does sedFit do?
sedFit is a spectral energy distribution fitting program. It takes photometry, both broad- and narrow-band (and all flavors inbetween) and attempts to fit a spectral template to those photometric data points. sedFit can work with spectra as well, insofar that spectra really are just a wavelength series of extremely narrowband photometry.

Important safety tip: sedFit runs using octave; however, newer versions of octave seem to not play well with sedFit. It currently runs on the Ubuntu shell using octave 2.1.73; octave 2.9 and later does not appear to work with sedFit.

Input templates for sedFit
sedFit is flexible and will take pretty much any spectral template you throw at it. Currently the empirical templates of Pickles (1998) are the favorite in that they are empirical templates - no model dependence. Model templates are allowable, however, if one so desires, so such things as NexGen, Phoenix, Kurucz, etc. area all allowable.

Command line invocation of sedFit
sedFit is usually invoked with a command line structure that involves:
$ sedFit [spectral template file] [photometry file]
Additionally, there are some nifty tools embedded in getCal which will automatically collect a lot of this photometry for you. This is very useful if you're wrestling with a lot of stars. In practice, this can be quite messy:
$ ~/mscSoftware/bin/fbolFormat -strom -geneva -2Mass -longWL HD217014 > HD217014.phot
$ ~/develop/sed/sedFit ~/mscSoftware/data/catalogs/pickles/data/main_sequence/ukg2iv.dat HD217014.phot
Details on photometry files is available, including the nifty python script and its supporting wrapper shell script getAllPhotometry.batx.

Alexa Hart wrote some notes on that may be of use to you as well.

Command line options
There are a few very useful command line options:
-AV [value] : tells sedFit to impose a reddening value AV
-fitAV : tells sedFit to iterate on a reddening value until it finds a best fit AV. Gives an error bar on AV as well (very useful!). Important safety tip: this option can be very time consuming (eg. ~10 minutes to run the code). This can be reduced by using -fitAV and -AV together and providing a good initial guess for AV.

Output of sedFit
sedFit will report the following values for the best fit of the photometry to the template: a chi^2 per degree of freedom value, an estimate of the bolometric flux of the source (both before and after reddening), a diameter estimate, and (if indicated, see below) a reddening value. What sedFit does NOT fit is template temperature: this is a fixed value associated with the template that goes into the fit and is used to extract an angular size estimate from the process.

These values are reported textually on the command line window, but of some additional interest is the graphic output: a postscript file is generated detailing the fit. Here are some examples (a fairly boring G0IV star) and (a moderately distant M giant with some reddening).