This add-on contain easy-call functions to interpolate and extrapolate. By: Manuel Astros All functions are developed to behave in similar way that the interpolation add-in created by Jose Ivan Martinez Garcia for Excel. It will make possible a kind of interoperability among LibreOffice-Calc, Google-sheet in interpolation matter. Packaged Functions included in this addin until now: interpo(x, XRange, YRange) : Linear interpolation with one parameter and two source ranges interpo2(x, y, Range) : Linear interpolation with two parameters and a table source cercha(x, Range, keyArg, V1, V2) : Spline interpolation with one parameter and a table source range cerchapi(Range, keyArg, v1, v2) : Determine the initial slope (1st derivative) at the first point of first spline cerchapf(Range, keyArg, v1, v2) :Determine the final slope at the last point of the last spline cerchaci(Range, keyArg, v1, v2) :Determine the initial curvature (2nd derivative) at the first point of the first spline cerchacf(Range, keyArg, v1, v2) :Determine the final curvature (2nd derivative) at the last point of the last spline Others functions will be added time by time, until all function implemented in the original Excel add-in are available here. Coming soon: video tutorial, cerchara, cerchamx and cerchamy.