Artificially inflates the number of landmarks

Interpolates supplementary landmarks that correspond to the mean coordinates of two adjacent landmarks.

Usage

landmarks_add(x, n = 3, smooth_iter = 0, plot = TRUE, nrow = NULL, ncol = NULL)

Arguments

x

A matrix, a data.frame a list of perimeter coordinates, often produced with object_contour(), landmarks(), or landmarks_regradi().

n

The number of iterations. Defaults to 3.

smooth_iter

The number of smoothing iterations to perform. This will smooth the perimeter of the interpolated landmarks using poly_smooth().

plot

Creates a plot? Defaults to TRUE.

ncol, nrow

The number of rows or columns in the plot grid when a list is used in x. Defaults to NULL, i.e., a square grid is produced.

Value

A Matrix of interpolated coordinates.

Examples

library(pliman)

# equally spaced landmarks
plot_polygon(contours[[4]])
ldm <- landmarks_regradi(contours[[4]], plot = FALSE)
points(ldm$coords, pch = 16)
segments(mean(ldm$coords[,1]),
         mean(ldm$coords[,2]),
         ldm$coords[,1],
         ldm$coords[,2])

ldm_add <- landmarks_add(ldm, plot = FALSE)
points(ldm_add, col = "red")
points(ldm$coords, pch = 16)

# smoothed version
ldm_add_smo <- landmarks_add(ldm, plot = FALSE, smooth_iter = 10)
lines(ldm_add_smo, col = "blue", lwd = 3)