lte-codes sterne spectrum ffit sfit grids idlines
commands scl
scl com sfit slv syn spc ga

Sfit Control Language: Classified Listing


show [>parameter_group< | all] : show values associated with a given parameter group
define >macro_name< : define a macro
run >macro_name< : run a previously defined macro
end: exit program
exit: exit program
quit: exit program

SFIT commands

valid : summarise current valid SFIT mode/method combinations

method_formal: Compute formal solution
method_levenburg: Select Levenburg-Marquardt method
method_amoeba: Select downhill simplex method
method_genetic: Select genetic algorithm method
method_chisq: Locate minimum chi^2 in grid
method_tolerance <tol>: Set tolerance (or convergence criterion)
meth_range <w1> <w2>: Set wavelength range for fit

data_spectrum<name> : data in "spectrum" format
data_flux_units<name> : flux units of data (default "normalized")
data_flux_scale<scale> : factor to scale flux (default 1)
data_pamela<name> : data in "pamela" format (w,f,s)
data_sigma<sigma> : define mean standard error in data
data_instrument<delta_wl> : define instrumental broadening (FWHM)
data_instrument<R> : define instrumental resolution R = wl / delta_wl (>1000)
data_cosmic<threshold> : define rejection threshold (eg cosmic ray)
data_drift<dv> : define velocity drift through exposure (km/s)
data_line_set | data_lines | dls <wl> <dw>: define line to to emphasize or include in fit
data_mask_set | data_masks | dms <w1> <w2> <sigma> : define interval (mask) to emphasize or exclude from fit
data_mask_disp | data_maskd | dmd : display current mask
data_mask_clear | dmc : dlear current mask

cont_reg_set <w1> <w2> : defines regions to be used in fitting a continuum
cont_reg_disp : display current continuum regions
cont_reg_clear : Clear current continuum regions
cont_poly <np> : Polynomial of order <np> to fit continuum
cont_filter <w> : Gaussian filter with FWHM w through ratioed spectrum
cont_special <w> <w2> : Gaussian filter with bad point rejection
cont_sigma : Computes standard deviation of data in continuum and applies it to current data
normalize : Normalizes the current spectrum using the defined continuum

data {...}: Define observational data and associated parameters
mask {...} : forces given spectral regions to be omitted from the fit
cmask {...} : Defines wavelength regions to be used in fitting a continuum
continuum {...}: Defines how a spectrum will be (re-)normalized
parameters {...} : Initialise all "slv" parameters
method {...}: Define method and associated parameters

SLV commands

models,model2 : read grid of model spectra
save_grid <file> : save model grid to binary file
read_grid <file> : read model grid from binary file
make_grid : reads models and saves tetrahedralized grid directly to a binary file
load_grid <file> : reads tetrahedralized model grid
grid_log_he : Convert the abundance grid to log scale

slv_... <p1> <p2> : Initialise parameter for solve
fix_... <p1> : Fix parameter for solve

solve : find optimum fit in a grid of model spectra

SYN commands

NB: synth uses multiple calls to spectrum, so various Spectrum commands may also be required.

synth : find optimum fit by adjusting abundances, vturb, vsini, and vrad

sterne <model> : Define the model atmosphere to be used by synth
syn_vturb <vturb> [<dv>]; Initialise vturb (km/s) for a fit using synth (default 5)
syn_vsini <vsini> [<dv>]; Initialise vsini (km/s) for a fit using synth (default 0)
syn_vrad <vrad> [<dv>]; Initialise vrad (km/s) for a fit using synth (default 0)
syn_beta <beta> Define limb darkening coefficient for a fit using synth (default 1.5)
save <fit> : Save the spectrum and best fit from synth

abundances {...} : Initialise abundances and microturbulence for synth

Spectrum commands

spc_... <p1> : Define parameters controlling operation of SPECTRUM

spc_nsource <nsource> : Switch for method used to compute source function (def: 3)
spc_nmode <nmode> : Switch for Spectrum mode of operation (def: 11)
spc_ntheta <ntheta> : Number of angles at which specific intensity is to be computed (def: 0)
spc_noptyp <noptyp> : Switch for choice of continuous opacities (QUB/KIEL/OP) (def: 1=KIEL)
spc_nhedat <nhedat> : Switch for choice of HeI data (BCS or Montreal) (def: 1=BCS)
spc_nhestark <nhestark> : Switch for choice of HeI Stark coefficients (def: 2)

Genetic algorithm parameters

gen_par {...} : Define parameters for controlling performance of genetic algorithm

This page is maintained by:
Simon Jeffery (
Last modified: Tue Oct 19 10:57:10 BST 2004