Sets or reads the variation mode of the n-the fit parameter. The following values are implemented at present:
mode meaning
-1 Frozen
0 Downhill simplex
1 Computed from master parameters by formula
2 Fit on a grid with 10 points
3 Fit on a grid with 20 points
4 Fit on a grid with 50 points
5 Fit on a grid with 100 points