Editing Interpolation (section)

==Related concepts==
The term ''[[extrapolation]]'' is used to find data points outside the range of known data points.

In [[curve fitting]] problems, the constraint that the interpolant has to go exactly through the data points is relaxed. It is only required to approach the data points as closely as possible (within some other constraints).  This requires parameterizing the potential interpolants and having some way of measuring the error.  In the simplest case this leads to [[least squares]] approximation.

[[Approximation theory]] studies how to find the best approximation to a given function by another function from some predetermined class, and how good this approximation is. This clearly yields a bound on how well the interpolant can approximate the unknown function.