# Spline Command

From GeoGebra Manual

- Spline( <List of Points> )
- Creates a cubic spline through all points.
- Spline( <List of Points>, <Order ≥ 3> )
- Creates a spline with given order through all points.
- Spline( <List of Points>, <Order ≥ 3>, <Weight Function> )
- Creates a spline with given order through all points. The weight function says what should be the difference of
*t*values for point*P*_{i}and*P*_{i+1}given their difference*P*_{i+1}-*P*_{i}= (*x*,*y*). To get the spline you expect from "function" algorithm you should use`abs(x)+0*y`

, to get the GeoGebra's default spline you can use`sqrt(x^2+y^2)`

. **Note:**The choice of default makes the result behave nicely when transformed, making sure that`Rotate(Spline(list), a)`

gives the same as`Spline(Rotate(list, a))`

.

## Comments

The result of the spline command is a curve. Spline algorithm is used for x and y coordinates separately: first we determine values of t that correspond to the points (based on Euclidian distances between the points), then we find cubic splines as functions t->x and t->y.