Adjusts the indicated data sets' correction norm by a single multiplicative
factor that minimizes the fit statistic. This approach to fitting the
correction norm is considered an INTERIM solution.
XSPEC> recornrm [<file range>...]
where <data set range> := <low data set>[-<high data set>]
(see the notes on ranges under input formats). All the data sets
specified by the one or more data set ranges on a single invocation of the command are
multiplied by a single number, which is chosen to best reduce the fit statistic. If
no ranges are given, then the last SINGLE range input is used. If you
wish to fit a data set's correction norm individually, then refer only to that data set.
Note: The use of the recornom command requires that a response and model be defined. It is perhaps best if a preliminary fit is performed. The user then should alternate between fit's and recornrm's until a stable solution is achieved. If the model is not a good fit, this process may not converge.