**Graph scaling and lin/log control**
Here you can choose the scaling of the data

plots and the 3D scatterplots.

Log plots require data values greater than zero.

X Scale (2D Only) | | Y Scale (2D Only) | | Z Scale (2D Only) |

| | | | |

**Animation and Graph size**
Here you can choose the size of the graphs. Smaller size files load quickly,

with less resolution while large files show more resolution but load more slowly.

**Hold Coefficients Constant**
Here you can enter values to hold coefficients constant during fitting.

Leave the entry field blank to let the coefficient fit normally.

Note that coefficient bounds are overridden by holding a coefficient constant.

z = amplitude * cosh(pi * (xy - center) / width)

z = z + (d * x) + (f * y) + g

**Estimated Initial Coefficients**
Here you can enter values for initial parameter estimates.

Few users will need this section, as the site estimates initial

parameters using the Differential Evolution genetic algorithm

for both non-linear equations and non-Gaussian fitting targets.

z = amplitude * cosh(pi * (xy - center) / width)

z = z + (d * x) + (f * y) + g

**Coefficients Bounds**
Here you can enter coefficient upper and lower bounds. Leave the

entry fields blank to let the coefficients fit without bounds.

Note that holding a coefficient constant overrides these bounds.

z = amplitude * cosh(pi * (xy - center) / width)

z = z + (d * x) + (f * y) + g