====== (old) Usage ======

For code version 2.0 (old release)

[[usage|go here for recent versions]]

===== Setup of model data =====


  - Download the base data archive (here). Set an environement variable PATHMODEL pointing to the snfit_data directory.
  - Download some instruments (here) and save them in the snfit_data directory. Edit snfit_data/fitmodel.card to point to the instruments. The key name has to match the one in the lightcurve.
  - Download SALT2 (or/and SALT1) templates (salt2_model_data-[version].tar.gz and/or salt_model_data-1-0.tar.gz), save them in the snfit_data directory, and edit snfit_data/fitmodel.card.

===== Installation of the code =====

  tar zxvf snfit_src-[version].tar.gz
  cd snfit
  configure --prefix=[where_you_want]
  make
  make install


==== For mac intel, try : ====


  configure --prefix=[where_you_want] --enable-gfortran

(S. Bailey needed to set environment variable MACOSX_DEPLOYMENT_TARGET=10.3 despite the fact that he runs Mac OS 10.4)

Download the file ''install-salt2.0.sh'' in the directory where you want to install the package and execute it (you need to do a ''chmod u+x install-salt2.0.sh'' first, you also need to have wget installed). The versions that are proposed here for download are the ones used in Guy et al. (2007), with compilation bug fixes but there might be newer versions of any of those files today. So this installation script should be considered as an example for a complete installation and test.

===== Light curves Input format =====

Assumed format (if you want to use another one, edit the MeasuredData class) :
One directory per supernova containing :
  * ''lightfile'' (ASCII file with redshift, Galactic E(B-V), ...)
  * Several light curve files for each instrument/filter.

''Example, files :''

  1994D/lightfile
  1994D/lc2fit_U.dat
  1994D/lc2fit_B.dat
  1994D/lc2fit_V.dat

''lightfile :''

  NAME           1994D
  RA             12:34:02.3950
  DEC            +07:42:05.700
  EPOCH          2000.0
  Redshift       0.00266901307822
  z_heliocentric 0.001494
  z_cmb          0.00266901307822
  MWEBV          0.02228


''1994D/lc2fit_B.dat :''

  #Date :
  #Mag :
  #Magerr :
  #end :
  @INSTRUMENT STANDARD
  @BAND B
  @MAGSYS VEGA
  49420.900000 14.230000 0.001943
  49422.830000 13.290000 0.001175
  49423.900000 12.890000 0.000907
  ...

(''INSTRUMENT'' name matches entry in ''fitmodel.card'',
''BAND'' is one the bands listed in ''snfit_data/Instruments/Landolt-1/FilterWheel'')

There is also a lightcurve format with fluxes, errors and zero points.

''Example, SNLS-03D4ag/lc2fit_g.dat :''

  @INSTRUMENT MEGACAM
  @MAGSYS VEGA
  @BAND g
  @WEIGHTMAT flux_per_night_weightmat_g.dat
  #Date :
  #Flux :
  #Fluxerr :
  #ZP :
  #end
  176.54 10267.351 95.517 32.2024 
  185.59 24423.189 102.738 32.2024 
  212.53 6733.480 144.903 32.2024 
  ...

(Here, an additional file is mentionned : the covariance matrix of the flux measurements)

===== Usage of the lightcurve fitter =====

By default SALT1 is used. Use option ''-m salt2'' for SALT2.
Options ''-e'' and ''-k'' permit to propagate the model uncertainties (diagonal and k-correction uncertainties, see section 6 of the paper).

  snfit lightcurve1 lightcurve2 ... 
  -s spectrum_file_name    : fit this spectrum as well
  -m modelname             : salt or salt2, default is salt(1)
  -1                       : only one obsevred band fitted 
  -2                       : max 2 observed band fitted 
  -3                       : max 3 observed band fitted 
  -r  phasemin phasemax    : range of phases to be fitted (default is -15,+40)
  -f stretch/color/daymax/X1/gtype ...        : fix a value 
  -p stretch/color/daymax/...      : add a prior 
  -f X{0,1,2,3,4}  value   : for salt2
  -z                       : fit redshift
  -i z value               : initial value of redshift
  -c #                     : number of calib. params. for spectra (def 1)
  -w wmin wmax             : allow SALT1/2 to fit in this wavelength range
  -e                       : use (diagonal) model uncertainties in chi2 
  -E                       : apply error floor for nearby SNe 
  -k                       : use k-correction uncertainties in chi2 
  -U  #                    : add obs. U-band calib. error
  -M                       : run minos at the end


Combination of options used in Guy et al (2007) :

''snfit lc2fit*.dat -r -15 +45 -f rv 3.1 -f ebv 0 -m salt2 -e -k -U 0.085 -f X2 0 -w 2900 7000''

Warning : In order to find the same results using salt1 with this code compared to versions
For photometric redshifts, you need to give an initial value using option ''-i z #'' so that when the code checks the lightcurves for which it can provide a model, it does not discard all of them (default redshift is 0.05)!

You can write the lightcurves of the model with ''snlc'' :

  snlc writes an ASCII file with the lightcurve of the model
  usage : snlc lightcurve1 lightcurve2 ... -p filename

''filename'' is the path of the output file of snfit: (i.e. ''result_salt.dat'' or ''result_salt2.dat'')