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|
|WEIGHT||weighting for statistic|
|USE_NUMERICAL_DIFFER||calculate parameter derivatives numerically|
|COSMO||cosmology parameters (, , )|
|GRAPH||graphics package (plt only)|
|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|
|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.