This menu contains variables which control the performance of the Marquardt-Levenberg (M-L) non-linear least squares fitting.

- FIT OPTIONS
- ONE One iteration only
- FLOAT Allow calibration to float
- OPT. Optimize step size for M-L.

- LAMBDA Gradient-Brute force parameter
- TOLERANCE Ratio of smallest over largest eigenvalue allowed
- CONVERGENCE Convergence criterion as ratio of new over previous

Choosing the OPT. option will cause a one-time delay before starting
M-L, including the loading of the interferometric data a second time as the
optimization of the step size overwrites the currently loaded visibilities.
The step size data are written into a file *Z_h_steps.xdr*.

Christian Hummel 2017-06-29