R: Computation of Bezier curve

bezier {fastmatrix} | R Documentation

## Computation of Bezier curve

### Description

Computes the Bezier curve based on n+1 control points using the De Casteljau's method.

### Usage

    bezier(x, y, ngrid = 200)

### Arguments

`x, y` | vector giving the coordinates of the control points. Missing values are deleted.
`ngrid` | number of elements in the grid used to compute the smoother.

### Details

Given \bold{p}_0,\bold{p}_1,…,\bold{p}_n control points the Bezier curve is given by B(t) defined as

B(t) = ≤ft({\begin{array}{c} x(t) \\ y(t) \end{array}}\right) = ∑\limits_{k=0}^n {n \choose k} t^k (1 - t)^k\bold{p}_k

where t\in[0,1]. To evaluate the Bezier curve the De Casteljau's method is used.

### Value

A list containing `xgrid` and `ygrid` elements used to plot the Bezier curve.

### Examples

    # a tiny example
    x <- c(1.0, 0.25, 1.25, 2.5, 4.00, 5.0)
    y <- c(0.5, 2.00, 3.75, 4.0, 3.25, 1.0)
    plot(x, y, type = "o")
    z <- bezier(x, y, ngrid = 50)
    lines(z$xgrid, z$ygrid, lwd = 2, lty = 2, col = "red")

    # other simple example
    x <- c(4,6,4,5,6,7)
    y <- 1:6
    plot(x, y, type = "o")
    z <- bezier(x, y, ngrid = 50)
    lines(z$xgrid, z$ygrid, lwd = 2, lty = 2, col = "red")

[Package fastmatrix version 0.4 Index]