Chaikin's corner cutting algorithm smooths a curve by iteratively replacing every point by two new points: one 1/4 of the way to the next point and one 1/4 of the way to the previous point.
smooth_chaikin(x, wrap = FALSE, refinements = 3L)
numeric matrix; 2-column matrix of coordinates.
logical; whether the coordinates should be wrapped at the ends, as for polygons and closed lines, to ensure a smooth edge.
integer; number of corner cutting iterations to apply.
A matrix with the coordinates of the smoothed curve.
This function works on matrices of points and is generally not called
directly. Instead, use
method = "chaikin" to apply this
smoothing algorithm to spatial features.
The original reference for Chaikin's corner cutting algorithm is:
Chaikin, G. An algorithm for high speed curve generation. Computer Graphics and Image Processing 3 (1974), 346–349
This implementation was inspired by the following StackOverflow answer:
# smooth_chaikin works on matrices of coordinates # use the matrix of coordinates defining a polygon as an example m <- jagged_polygons$geometry[][] m_smooth <- smooth_chaikin(m, wrap = TRUE) class(m)#>  "matrix" "array"class(m_smooth)#>  "matrix" "array"plot(m, type = "l", axes = FALSE, xlab = NA, ylab = NA)lines(m_smooth, col = "red")# smooth is a wrapper for smooth_chaikin that works on spatial features library(sf) p <- jagged_polygons$geometry[] p_smooth <- smooth(p, method = "chaikin") class(p)#>  "XY" "POLYGON" "sfg"class(p_smooth)#>  "XY" "POLYGON" "sfg"plot(p)plot(p_smooth, border = "red", add = TRUE)