Consider an example of a model dataset GX7 with a model AG*BR in a file BR_MOD. Invoke SGRID,
> SGRID GX7 BR_MOD
SGRID Version 1.7-0 ; Version id and user
; informed of inputs
...
Existing model is: AG*BR ; User is informed of all
; model parameters, with
; lower bound, current
; value and upper bound.
(1) hydrogen column density (1.0E21 /cm**2) .. .. ..
(2) em10 (1e60cm**-3/(10kpc)**2) .. .. ..
(3) temperature (keV) .. .. ..
PARS - Parameters for grid axes > 2 3 ; Select those parameters
; to form the grid axes
OPT - How to specify grid axes /1/ > ; Specify how spacing of
; grid axes to be done
All grid axes will be linearly spaced
; User now selects range for each grid axis. The default offered
; is the lower-upper bound, which will usually be too large. The
; number of bins is also selected.
Enter axis values in units of 1e60cm**-3/(10kpc)**2
AXIS1 - Range of 1st grid axis /'9.9999997E-05:100'/ > 40:50
NBIN1 - Number of grid values in 1st axis > 10
Enter axis values in units of keV
AXIS2 - Range of 2nd grid axis /'0.1:20'/ > 4:5
NBIN2 - Number of grid values in 2nd axis > 10
GPARS - Parameter(s) to be gridded ; Select the values to grid.
(0 for fit statistic) /0/ > 0 1 ; Here we choose to grid
; both the fit statistic and
; the hydrogen column.
AUTO - Automatic naming of output ; We'll choose our output
files /YES/ > NO ; file names
OUT1 - Output filename for 1st grid > grid_chi
OUT2 - Output filename for 2nd grid > grid_nh
; SGRID now does the work
There are free non-grid parameters - optimising at each grid point.
; The best fit grid point is reported on completion
The minimum value of chi-squared in the grid is 1961.189
SUBSTAT - Subtract minimum value of statistic from grid /NO/ >
> SGRID GX7 BR_MOD PARS=2,3 GPARS=0 ; Construct 10 x 10 grid
NBIN1=10 NBIN2=10 OUT=GRID_CHI \ ; over default region
> SGRID GX7 BR_MOD PARS=2,3 GPARS=0 ; Construct 10 x 10 grid
NBIN1=10 NBIN2=10 OUT=GRID_CHI \ ; over default region
> SGRID MK41 AMODEL Z=0.006 ; Invoke with a redshift