The following is a list of the commands available in XSPEC, together with a brief description of the purpose of each. The commands have been categorized under six headings: Control, Data, Fit, Model, Plot, and Setting. The Control commands contain the interface with the operating system: they cause commands to be executed, or user input written to disk, or control how much is output. The Data commands manipulate the data being analyzed, by reading data into the program or replacing spectra or their ancillary detector, background, correction, or efficiency (auxiliary response) arrays. Additionally data commands control the channels under analysis. The fit commands invoke the fitting routines, modify their behavior by interchanging fitting algorithms or statistics in use, fixing parameters, or perform statistical testing. The Model commands create or manipulate the model, adding or editing components, modifying parameters, or alternatively performing analytical calculations from a model. The Plot commands deal with all aspects of plotting. Finally the Setting commands sets variables that affect theoretical models.
Command |
Category |
Description |
abund |
Setting |
Set the abundance table. |
addcomp |
Model |
Add a component to the model. |
addline |
Model |
Add lines to a model |
arf |
Data |
Read an auxiliary response file. |
autosave |
Control |
Periodically save the XSPEC status. |
backgrnd |
Data |
Reset the files to be used for background subtraction. |
chatter |
Control |
Control the verbosity of XSPEC. |
corfile |
Data |
Reset the files to be used for background correction. |
cornorm |
Data |
Reset the normalization to be used in correcting the background. |
cosmo |
Setting |
Set H0, q0, and |
cpd |
Plot |
Alias for setplot device. |
data |
Data |
Input one or more PHA data files. |
delcomp |
Model |
Delete a component from the model. |
diagrsp |
Data |
Diagonalize the current response for an ideal response. |
dummyrsp |
Model |
Create a dummy response, covering a given energy range. |
editmod |
Model |
Add, delete, or replace one component in the model. |
energies |
Model |
Specify new energy binning for model fluxes. |
eqwidth |
Model |
Calculate a model component’s equivalent width. |
error |
Fit |
Determine a single parameter confidence region. |
exec |
Control |
Execute a shell command from within XSPEC. |
exit |
Control |
Wind up any hardcopy plots and exit from XSPEC. |
extend |
Model |
This is now obsolete. See energies command. |
fakeit |
Data |
Produce simulated data files for sensitivity studies. |
fit |
Fit |
Find the best fit model parameters. |
flux |
Model |
Calculate the current model's flux over an energy range. |
freeze |
Fit |
Do not allow a model parameter to vary during the fit. |
ftest |
Fit |
Calculate the F-statistic between two model fits |
gain |
Model |
Perform a simple modification of the response gain. |
goodness |
Fit |
Monte Carlo calculation of goodness-of-fit. |
hardcopy |
Plot |
Spool the current plot to the printer. |
help |
Control |
Obtain help on XSPEC commands. |
identify |
Model |
List possible lines in the specified energy range. |
ignore |
Data |
Ignore a range of PHA channels in future fit operations. |
iplot |
Plot |
As plot command but interactive using PLT. |
log |
Control |
Open the log file to save output. |
lumin |
Model |
Calculate the current model's luminosity over a given rest frame energy range and redshift. |
method |
Fit |
Set the minimization method. |
model |
Model |
Define the model to be used when fitting the data. |
modid |
Model |
Guess line IDs in the model. |
newpar |
Model |
Modify the model parameters. |
notice |
Data |
Restore a range of PHA channels for future operations. |
plot |
Plot |
Plot various information on the current plot device. |
query |
Control |
Switch on/off prompt to continue fitting. |
quit |
Control |
An alias for exit |
renorm |
Fit |
Adjust the model norms, and/or control automatic renorming. |
response |
Data |
Reset the files used to determine the detector responses. |
save |
Control |
Save aspects of the current state to a command file. |
script |
Control |
Open the script file to save all commands input. |
setplot |
Plot |
Modify the plot device and other values used by the plot routines. |
show |
Control |
Display current file and model information. |
source |
Control |
Execute a script file. |
statistic |
Fit |
Change the fit statistic in use. |
steppar |
Fit |
Step through a range of parameter values; perform a fit at each step. |
syscall |
Control |
Run a shell command. |
systematic |
Model |
Set the model systematic error. |
tclout |
Control |
write xspec data to a tcl variable |
tcloutr |
Control |
tclout with return value |
thaw |
Fit |
Allow a model parameter to vary during the fit. |
thleqw |
Model |
Calculates expected fluorescent line equivalent width. |
time |
Control |
Display elapsed time and other statistical information. |
uncertain |
Fit |
Alias for error |
untie |
Model |
Untie linked parameters. |
version |
Control |
Print XSPEC version and build date/time |
weight |
Fit |
Change the weighting function used for chi-squared fits. |
xsect |
Setting |
Change the photoelectric absorption cross-sections in use. |
xset |
Setting |
Modify a number of XSPEC internal switches |