From: VAXN::LAO
Date:  4-JUN-1993  16:16:20
Description: Fitting Using MSE Data                                  

There are two SNAP files available to use with the multi-channel
MSEs.  Both can be obtained from the EFIT: area on the Vaxs
or the /link/efit area on the HPs
 
          efit_snap.dat_mse1
          efit_snap.dat_mse2
 
The MSE1 SNAP file has one less fitting parameters then MSE2.
The current density profiles obtained using MSE1 usually are
smooth, whereas those using MSE2 tend to have fine structures.
This is similarly reflected in the condition number of the
fitting matrix.  The condition number from MSE1 is typically
a factor of 3 to 5 smaller than that from MSE2, although both
are acceptable.  Unless MSE1 give excessive high chi2 or
convergent error, we recommend using the MSE1 SNAP file
rather than the MSE2.
 
When using MSE data in the fitting, a significant amount of CPU
time is spent in setting up the response functions for MSE.
The response functions are stored in the file
 
      RSTARKXX.DAT
 
after making a run.  The CPU time can be reduced by renaming
this file appropriately for EFIT to read in
 
      RSnnnn_01.D3D for Vaxs and HP single precision
 
      RSnnnn_01.DDD for HP double precision
 
where nnnn representing the EFIT grid size.  For example,
3333 for 33x33, 3365 for 33x65, 129129 for 129x129, etc.
This is particularly handly when making time-dependent EFIT
runs.  It can reduce the processing time by a factor as much
as 2.
 
The fitting information is summarized in the plots.  These
include the location of the MSE viewing points, q values at these
points, chi2 due to MSE, a comparion of the fitted and the measured
pitch angles and a plot of the individual chi2.