Statistics - Splines

Data Mining - (Global) Polynomial Regression (Degree)

polynomials regression Although polynomials are easy to think of, splines are much better behaved and more local. Articles Related Procedure With polynomial regression, you create new variables that a "...

Data Mining - Step Function (piecewise constants)

Step functions, are another way of fitting non-linearities. (especially popular in epidemiology and biostatistics) Articles Related Procedure Continuous variable are cut into discrete sub-ranges and f "...

R - Spline

Fitting splines in R is easy: bs(x, ...) for any degree splines (one: linear spline, three: cubic spline and ns(x, ...) for natural cubic splines, in package splines. Articles Related

Statistics - (Linear spline|Piecewise linear function)

A linear spline, or piecewise linear function has a degree zero and is: linear in the left and the right. forced to be continuous at the knot. Articles Related Definition / Representationglobal pol "...

Statistics - Cubic spline

Cubic splines is a step cubic piecewise polynomial in the left and the right and continuous at the knot. There's the following constraints: The first derivatives continues at the knot, and the seco "...

Statistics - Natural (Cubic) Spline

A natural cubic spline is a cubic spline where two extra constraints have been added at the boundaries (on each end). The goal of this constraints is to avoid as for global cubic polynomial that the t "...

Statistics - Non-linear (effect|function|model)

Non-linear effect The truth is almost never linear but often the linearity assumption is good enough. (Linearity is an approximation) When its not (increasing in complexity): polynomials, step funct "...

Statistics - Piecewise polynomials

Piecewise polynomials generalize the idea of piecewise constants. The idea try to get rid of the global polynomial because it's global and not local. Instead of having a single polynomial over the wh "...