4.5. Config object

The Config object contains all of DEMETER's configuration parameters as well as providing an simple way for user-defined parameters to be stored and made available to the templating system.

At start-up, DEMETER reads the DEMETER configuration files, then updates those values from the demeter.ini file, which is stored in $HOME/.horae on unix systems and in %APPDATA%/demeter on Windows systems.

To make the Config object readily accessible at all times in your program, the co method is a method of the base class and is inherited by all DEMETER objects. Thus, given any object, you can “find” the Config object like so:

$the_config_object = $any_object -> co;

Any method of the plot object is easily called by chaining with the co method. For example to get the configured default value for the bkg_rbkg attribute of the Data object, you do this

$any_object -> co -> default('bkg', 'rbkg');

4.5.1. The configuration file format

This is the configuration file for the parameters controlling the back-Fourier transform of data. The format of the file is somewhat rigid in order to simplify the parsing of these files.

######################################################################
section=bft
section_description
  These parameters determine how backward Fourier transforms
  are done by Demeter.

variable=dr
type=real
default=0.0
units=Angstroms
description
  The default width of the window sill used in the backward Fourier
  transform.  0 is used if this is set to less than 0.

variable=rwindow
type=list
default=hanning
options=hanning kaiser-bessel welch parzen sine
description
  The default window type to use for the backward Fourier transform.

variable=rmin
type=real
default=1
units=Angstroms
description
  The default value for the lower range of the backward Fourier
  transform.

variable=rmax
type=real
default=3
units=Angstroms
description
  The default value for the upper range of the backward Fourier
  transform.

4.5.2. User-defined configuration files

4.5.3. Using and resetting configuration parameters

4.5.4. The Config object and the templating system

4.5.5. WxWidgets and the configuration system

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