XSPEC Tcl scripts

The XSPEC command interface is now mediated through the Tcl scripting language. This means that many new powerful features are available eg looping, conditionals, and ascii file i/o. We have created a simple example script to demonstrate these features. It should be possible to use this script as a template to do many iterative operations with xspec. To run it just give xspec the command @tclex.tcl.

For the more ambitious the following useful Tcl scripts have been written by Andy Ptak. To run any within xspec they must first be loaded using source tcl_filename. xspec will write the names and argument strings for the tcl procedures that have just been loaded. To get more information on a tcl procedure give xspec the command tcl_procedure ?.

dof.tcl computes the number of degrees of freedom.
fek_search.tcl searches for Fe-K emission by fitting a wabs (po + ga) model with the energy free, fixed at 6.4 and 6.7 and sigma free, fixed at 0.01, 0.1, and 0.5 keV. Gets errors on all parameters.
mean.tcl computes mean of values in a list.
qdp1.tcl creates a qdp file from a list of values.
qdp2.tcl creates a qdp file from two arguments, one a list of x values and the second a list of y values.
setup_mod.tcl sets up complex models with initial params, ties relevant params. if multiple data groups are present.
smart_error.tcl steps parameter using smart_step until a desired deltachisq is reached and interpolates to get error. Warns if relative mininma are present and produces qdp plot of delta-chisq vs. param. value.
smart_fit.tcl drives smart_error for all relavent params. in a model (defined in smart_fit_config.dat), puts results in a log file of the form:
```
                Nh = 0.11 (0.05-0.65)
                Gamma = 1.75 (1.70-1.80)
                chisq(dof) = 165.5/154
                F(0.5-2.0 keV) = ...
    
```
If a new minimum is encountered, the new best fit is saved and the error determination is restarted from the beginning.
smart_step.tcl similar to built-in command steppar, restarts step if new min. is found and returns status flag.

Keith Arnaud

Last modified: Thu Jan 29 16:11:56 EST