Editing Numerical analysis (section)

===Interpolation, extrapolation, and regression===
[[Interpolation]] solves the following problem: given the value of some unknown function at a number of points, what value does that function have at some other point between the given points?

[[Extrapolation]] is very similar to interpolation, except that now the value of the unknown function at a point which is outside the given points must be found.<ref>{{cite book |last1=Brezinski |first1=C. |last2=Zaglia |first2=M.R. |title=Extrapolation methods: theory and practice |publisher=Elsevier |date=2013 |isbn=978-0-08-050622-7 |url={{GBurl|WGviBQAAQBAJ|pg=PR7}}}}</ref>

[[Regression analysis|Regression]] is also similar, but it takes into account that the data are imprecise. Given some points, and a measurement of the value of some function at these points (with an error), the unknown function can be found. The [[numerical methods for linear least squares|least squares]]-method is one way to achieve this.