make_segments function

Plot path connecting points on ggplot.

Convert x-y coordinates to a data.frame for geom_path plotting on ggplot.

make_segments(xy, N=nrow(xy))

Arguments

• xy: Matrix or data.frame of x-y points to plot as a path. If there are any rows that are NA-valued, the resulting path will consist of disconnected segments in those locations.
• N: Number of rows of xy to plot as a path. By default, the number of rows, so all of xy.

Author(s)

Samuel Ackerman

Examples

#generate toy dataset
library(ggplot2)
d <- as.data.frame(cbind(X=runif(50), Y=runif(50)))

#create segments with some missing lines so will be some gaps)
dseg <- d
dseg[ sample(20),] <- NA

g <- ggplot(d, aes(x=.data$X, y=.data$Y)) + theme_bw() 
g <- g + stat_density2d(aes(fill=after_stat(!!str2lang("density"))), geom="tile", contour=FALSE)
g <- g + scale_fill_gradient(low="white", high="black") + theme(legend.position="bottom")
g <- g + geom_path(data=make_segments(xy=dseg), aes(x=.data$X, y=.data$Y), colour="red", lwd=1.5) 
g