When you set the ‘Modelfit’ style on a scatterplot or line graph, the default is to draw a simple linear fit and determine the origin and slope of the line. Adding ‘Annotate’ to the style causes RainPro to append a note of these values to the line. To change the order of fit (e.g. to put a cubic curve through the points):

chSet 'Order' 3

The values may only be in the range 1-4 here.

Fitting models to 3D data
When the modelfit style is used with 3D data in a cloud chart, you may choose different values for the order of fit in the X and Y directions. For example if you think your data should be linear in X but possibly quadratic in Y, choose:

chSet 'Order'  1 2

Either value may be zero here, which effectively states that there is no relationship expected between the Z-values and the values on that axis. If both values are zero, a horizontal plane is plotted, showing the average Z-value.

See also ...
chCloud – 3D scatter plots
Coefficients – parameters from modelfit