sortCurve: sort curvepoints by using the subsequent neighbours

In Morpho: Calculations and Visualisations Related to Geometric Morphometrics

sort curvepoints by using the subsequent neighbours

Description

sort curvepoints by using the subsequent neighbours

Usage

sortCurve(x, k = 5, start = NULL)

Arguments

x	k x m matrix containing the 2D or 3D coordinates
k	number of nearest neighbours to look at. Set high for very irregularly clustered curves.
start	integer: which row of x to use as a starting point. If NULL, it is assumed that the curve is open and the point where the angle between the two nearest neighbours is closest will be chosen.

Value

xsorted	matrix with coordinates sorted along a curve
index	vector containing the sorting indices

Examples

## generate a curve from a polynome
x <- c(32,64,96,118,126,144,152.5,158)
y <- c(99.5,104.8,108.5,100,86,64,35.3,15)
fit <- lm(y~poly(x,2,raw=TRUE))
xx <- seq(30,160, length=50)
layout(matrix(1:3,3,1))
curve <- cbind(xx,predict(fit, data.frame(x=xx)))
## permute order
set.seed(42)
plot(curve);lines(curve)
curveunsort <- curve[sample(1:50),]
## now the curve is scrambled
plot(curveunsort);lines(curveunsort,col=2)
curvesort <- sortCurve(curveunsort)
## after sorting lines are nice again
plot(curvesort$xsorted);lines(curvesort$xsorted,col=3)

Morpho documentation built on Feb. 16, 2023, 10:51 p.m.