point_distance {VoxR}

Computes the distance of a set of points to a user defined point.

Description

Computes the distance of a set of points to a user defined point.

Usage

point_distance(data, point, message)

Arguments

data

a data.frame or data.table containing the x, y, z, ... coordinates of a point cloud or voxel cloud.

point

a vector of length 3 containing the x, y and z coordintes of the reference point.

message

logical. If FALSE, messages are disabled. Default = TRUE.

Value

A vector containing the distance values of the points.

References

Lecigne, B., Delagrange, S., & Messier, C. (2018). Exploring trees in three dimensions: VoxR, a novel voxel-based R package dedicated to analysing the complex arrangement of tree crowns. Annals of botany, 121(4), 589-601.

Examples

#- import tls data
tls=data.table::fread(system.file("extdata", "Tree_t0.asc", package="VoxR"))

#- compute distance to the crown centre
tls[,dist:=VoxR::point_distance(tls,c(mean(x),mean(y),mean(z)))]

#- round distance values for visualization
tls[,dist:=round(dist*100)]

#- plot the distance to crown centre
cols=rev(rainbow(max(tls$dist)+1,end=4/6)) # color scale
rgl::open3d()
rgl::plot3d(tls,col=cols[tls$dist+1],add=TRUE)