Extrapolation - Wikipedia
https://en.wikipedia.org/wiki/ExtrapolationA sound choice of which extrapolation method to apply relies on a prior knowledge of the process that created the existing data points. Some experts have proposed the use of causal forces in the evaluation of extrapolation methods. Crucial questions are, for example, if the data can be assumed to be continuous, smooth, possibly periodic etc. Linear extrapolation means creating a tangent line at the end of the known data and extending i…
Linear interpolation - Wikipedia
https://en.wikipedia.org/wiki/Linear_interpolationIf the two known points are given by the coordinates and , the linear interpolant is the straight line between these points. For a value x in the interval , the value y along the straight line is given from the equation of slopes which can be derived geometrically from the figure on the right. It is a special case of polynomial interpolation with n = 1.