The data arrays are normally extracted from one of the Explain CURVE type objects. The fit is to an equation of the form y = mx + b. The fit results in estimates for m, b, a residual and a goodness-of-fit parameter.
The most common use of an Explain LINFIT object is in polarization resistance calculations. The data arrays are chosen to include a corrosion potential (where the current changes sign). If the x array is current and the y array is potential, the slope m is the polarization resistance with units of Ω. The LINFIT class can also be used for other purposes.