Specifying Alternate Versions of Calibration Constants in JANA

From Dmitry Romanov:

To specify an alternate version of calibration constants from CCDB, use the JANA_CONTEXT environment variable. The value of JANA_CONTEXT is passed to CCDB as a text string. The string may contain

• variation=<variation_name>
• calibtime=

Examples:

JANA_CALIB_CONTEXT="variation=john"

JANA_CALIB_CONTEXT="calibtime=2014-05"

JANA_CALIB_CONTEXT="variation=john calibtime=2014-05"

JANA_CALIB_CONTEXT can also be set as a command-line option to JANA, for example

???

Alternate versions can also be specified directly in C++ as an argument to the GetCalib function. The argument is a string of the form </path/to/data>:<run>:<variation>:<time>. For example,

loop->GetCalib("FDC/params:::2014-05", containerObject);

rather than the usual

loop->GetCalib("FDC/params", containerObject);