This is a read-only property which is maintained for you by RainPro to allow you to use the ‘modelfit’ style and then do your own chart notes with the details of the fit chosen.

coeff„ch.Query 'fit'

The result will be a numeric vector with 1 more element than the order of fit used. The default (order-1) is intercept and slope.

Typically, the coefficients would be used to format a neat version of the equation of the line, as here. You could also use the values for further processing, e.g. to provide forecast Y-values for specific inputs of interesting X-values by the user.

See also ...
OrderOfFit – polynomial degree of modelfit