Customizing XSPEC

The XSPEC environment can be customized using two separate files, both of which are searched for in the directory $HOME/.xspec

The first file, Xspec.init contains a number of settings that control items in XSPEC. The settings available are as follows.

USE_ONLINE_HELP whether to use on-line or local help files
LOCAL_HELP_FORMAT local help format (html or pdf)
PDF_COMMAND command to read pdf
HTML_COMMAND command to read html
GUI whether to use GUI mode (false only)
DUMMY argument for dummyrsp command
CHAT terminal and log chatter levels
XSECT photoelectric cross-section table
ABUND solar abundance table
METHOD fitting method
STATISTIC fit statistic
TESTSTAT test statistic
WEIGHT weighting for $S^2$ statistic
USE_CHAIN_RULE calculate parameter derivatives using the chain rule
COSMO cosmology parameters ($H_0$, $q_0$, $\lambda_0$)
GRAPH graphics package (plt only)
PLOTDEVICE plotting device
WAVE_PLOT_UNITS units for setplot wave mode
USER_SCRIPT_DIRECTORY directory for user scripts
FIT_DELTAS choice for parameters' fit delta values
ATOMDB_VERSION the AtomDB version number
NEI_VERSION the NEI AtomDB version number
PARALLEL Parallel processing settings
CONTOUR_IMAGE Put background image on contour plots

A copy of this file is placed in the $HOME/.xspec directory on XSPEC12's first start-up or when it is not found. After this users can modify settings such as default cosmology or the energy range for dummy response for their own requirements.

This is also the place where users can select if they want to view PDF help files from the XSPEC distribution or HTML either locally or from the HEASARC site. Setting USE_ONLINE_HELP to true uses the remote HTML files while false will use either PDF or HTML local files depending on the value of LOCAL_HELP_FORMAT.

The PDF_COMMAND and HTML_COMMAND entries determine which applications are run for the two viewing cases. The HTML_COMMAND value should typically just be the name of a web browser, or “open” for Mac OS X users. The default settings for the PDF_COMMAND entry are what work best for launching Adobe Acrobat Reader 7.0.x on Linux/Unix systems. For those launching earlier versions, the “-openInNewWindow” flag should be replaced with “-useFrontEndProgram”. For Mac users, again we recommend the entire entry simply be replaced with “open”.

The second file that is searched for is the xspec.rc file. This contains users' own customizations, for example Tcl or XSPEC command abbreviations, packages to be loaded on startup, or Tcl scripts containing procedures that are to be executed as commands. Please consult Appendix A and references/links therein for details of Tcl commands and scripting.