data_spectrum <name> : data in "spectrum" format
data_pamela <name> : data in "pamela" format (w,f,s)
data_flux_units <name> : flux units of data
"norm" for normalised data (default)
anything else and data are currently assumed to be F_lambda
data_flux_scale <scale> : factor to scale observed fluxes (default 1)
In cases where observed fluxes are typically 10-11 ergs/cm2/s/A, we find numerical errors when
inverting the covariance matrices. To avoid this, the data may be scaled by an arbitrary factor in
order to improve numerical stability.
data_sigma <sigma> : define mean standard error in data
data_instrument <delta_wl>|<R> : define instrumental broadening FWHM | R
Note two alternate uses of this command -- selected by the value provided. If the argument is >1000, it is assumed to be R = wl / delta_wl, and the data will be broadened as a fn of wavelentgth, otherwise the value is assumed to be a FWHM (in A) and the data will be broadened uniformly.
The command is marked for replacement with "data_resolution"
data_cosmic <threshold> : define rejection threshold (eg cosmic ray)
If any datum exceeds this value (default=1030), it will be assigned a large error (1030)
and will thus carry negligible weight in any subsequent fit. If set too low, such that more than 5% of data
points are rejected, this threshold will not be applied. To restore defaults, set <threshold> = 0.
data_drift <dv> : define velocity drift through exposure (km/s)
data_line_set | data_lines | dls <wl> <dw>:
Defines line to emphasize or include in the fit, by artificially reducing the local error (sigma) by a factor 100.
Repeat command to add additional lines. An entry of 0 0 clears all lines. So does
dmc
data_mask_set | data_masks | dms <w1> <w2> <sigma>:
Defines wavelength interval to emphasize or exclude from fit, by artificially modifying the local error (sigma).
Repeat command to add additional mask regions. sigma is the s.d. to apply to the data within the region to be masked.
An entry of 0 0 0 clears all regions. but see
dmc
data_mask_disp | data_maskd | dmd : Display current mask
data_mask_clear | dmc : Clear current mask
cont_reg_set | cont_regs | crs <w1> <w2>
: Defines wavelength regions to be used in fitting a continuum.
Repeat command to add additiona continuum regions. An entry of 0 0 clears all regions.
but see
cont_reg_clear
cont_reg_disp | cont_regd | crd,
cont_regd : Display current continuum regions
cont_reg_clear | crc : Clear current continuum regions
cont_poly <np> : Polynomial of order <np> to fit continuum
An nth order polynomial is fitted to this ratio in those
wavelength regions defined by "cmask".
The observed spectrum is then multipled by this polynomial to obtain a new spectrum
for use by SFIT.
cont_filter <w> : Gaussian filter with FWHM w through ratioed spectrum
A gaussian filter with FWHM = w is passed through the
ratioed spectrum. The observed spectrum is then multipled by this filter to obtain
a new spectrum for use by SFIT.
cont_special <w> <w2> : Gaussian filter with bad point rejection
a gaussian filter with FWHM = w2 is passed through the
ratioed spectrum wavelength. Points more than 3-sigma from this local mean value
are deleted. A second gaussian filter with FWHM = w is passed through the result.
The observed spectrum is then multipled by this filter to obtain a new spectrum
for use by SFIT.
cont_sigma : Computes standard deviation of data in continuum regions and applies it to current data
normalize : Normalizes the current spectrum using the defined continuum
Executes one normalization step and applies it to the current spectrum, using the current
parameter estimates, the method defined by
cont_poly or cont_filter
and the continuum regions defined by cont_reg_set.
This command takes no parameters