Session Parameters

Input data observed with the same configuration of the instrument and the parameters needed for the reduction define a session.

Session parameters are listed by the command SHOW/ECHELLE. It is recommended to use this command to control the actual status before executing any further reduction step. The command SHOW/ECHELLE displays only those parameters which must be set according to the options and methods chosen for the reduction. This enables to know exactly which parameters are required and available to tune the reduction.

Current parameters are saved with the command SAVE/ECHELLE name, where name is the session name. This command will be used whenever you want to interrupt a session which then can be restarted at any other time.

Current parameter values are set to the default value with the command INIT/ECHELLE, or set to the values of a previously saved session with INIT/ECHELLE name. INIT/ECHELLE is required each time you start the reduction of a new set-up or instrument.

The command HELP/ECHELLE provides a short on-line information on the echelle keywords. The keyword name can be truncated to a significant root name. The information consists of a description, the default and actual value. Four different modes are available:

• ``HELP/ECH'' without parameter, displays a general help message about the echelle package.
• ``HELP/ECH <keyword>'' gives a short description of the echelle keyword <keyword>.
• ``HELP/ECH method'' provides a list of method keywords
• ``HELP/ECH option'' provides a list of option keywords

Relevant session parameters can be defined for each command in the usual way:

command/qualifier parameters

or can be defined in explicit form as

SET/ECHELLE param=value [param=value ...]

where param is the parameter name and value is the assigned value. The assigned values will be maintained until you save them for later reference. Current parameter values are re--assigned either by INIT/ECHELLE or by another SET/ECHELLE command.

The direct assignment is possible as well, as in the following examples:

SLIT = 10
WLCLOOP(2) = 0.1
LINCAT = ``thar.tbl''